<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><Version>2.2.0.25</Version><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><ReportLongName>006130 - Disclosure - Commitments, contingencies and leases</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelColumn>false</LabelColumn><CurrencyCode>USD</CurrencyCode><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName>1/1/2010 - 12/31/2010
USD ($)

USD ($) / shares
</KeyName><CurrencySymbol>$</CurrencySymbol><contextRef><ContextID>c00026</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000935494</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2010-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2010-12-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS><UnitProperty><UnitID>u000</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>u001</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>u002</UnitID><UnitType>Divide</UnitType><NumeratorMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></NumeratorMeasure><DenominatorMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></DenominatorMeasure><Scale>0</Scale></UnitProperty></UPS><CurrencyCode>USD</CurrencyCode><OriginalCurrencyCode>USD</OriginalCurrencyCode></MCU><CurrencySymbol>$</CurrencySymbol><Labels><Label Id="1" Label="12 Months Ended" /><Label Id="2" Label="Dec. 31, 2010" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>nati_NotesToFinancialStatementsAbstract</ElementName><ElementPrefix>nati</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><NonNumericTextHeader /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>No definition available.</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Notes to Financial Statements [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_CommitmentsAndContingenciesDisclosureTextBlock</ElementName><ElementPrefix>us-gaap</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>terselabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;&lt;font style="DISPLAY: inline; FONT-WEIGHT: bold"&gt;Note 13&lt;/font&gt; &amp;#8211; &lt;font style="DISPLAY: inline; FONT-WEIGHT: bold"&gt;Commitments, contingencies and leases&lt;/font&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block"&gt;&lt;br /&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 27pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;We have commitments under non-cancelable operating leases primarily for office facilities throughout the world. Certain leases require us to pay property taxes, insurance and routine maintenance, and include escalation clauses. Future minimum lease payments as of December 31, 2010, for each of the next five years are as follows (in thousands):&lt;/font&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block"&gt;&lt;br /&gt;&lt;/div&gt;&lt;div align="left"&gt;&lt;table style="FONT-FAMILY: times new roman; FONT-SIZE: 10pt" cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td valign="bottom" width="88%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2011&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;$&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;14,530&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td valign="bottom" width="88%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2012&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;10,728&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td valign="bottom" width="88%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2013&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;7,757&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td valign="bottom" width="88%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2014&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;6,472&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td valign="bottom" width="88%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2015&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;5,476&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="88%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Thereafter&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;11,168&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td style="PADDING-BOTTOM: 4px" valign="bottom" width="88%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160; &lt;/font&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 4px" valign="bottom" width="1%" align="right"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;$&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;56,131&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 4px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block"&gt;&lt;br /&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 27pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;Rent expense under operating leases was approximately $13.5 million, $12.3 million and $11.7 million for the years ended December 31, 2010, 2009 and 2008, respectively.&lt;/font&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block"&gt;&lt;br /&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 27pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;As of December 31, 2010, we have non-cancelable purchase commitments with various suppliers of customized inventory and inventory components totaling approximately $7.6 million over the next twelve months.&lt;/font&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block"&gt;&lt;br /&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 27pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;As of December 31, 2010, we have outstanding guarantees for payment of customs, foreign grants and potential customer claims totaling approximately $5.3 million, generally over the next twelve months.&lt;/font&gt;&lt;/div&gt;</NonNumbericText><NonNumericTextHeader>Note 13 &amp;#8211; Commitments, contingencies and leasesWe have commitments under non-cancelable operating leases primarily for office facilities throughout the</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Includes disclosure of commitments and contingencies. This element may be used as a single block of text to encapsulate the entire disclosure including data and tables.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name FASB Interpretation (FIN)
 -Number 14
 -Paragraph 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name Statement of Financial Accounting Standard (FAS)
 -Number 5
 -Paragraph 9, 10, 11, 12

</ElementReferences><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Commitments, contingencies and leases</Label></Row></Rows><Footnotes /><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows><ReportName>Commitments, contingencies and leases</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>false</HasCustomUnits><SharesShouldBeRounded>true</SharesShouldBeRounded></InstanceReport>
