CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net loss	$ (10,061)	$ (10,518)	$ (17,679)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation	3,907	4,650	4,236
Tax benefit (deficit) from stock-based compensation	29	8	109
Excess tax benefit related to stock-based compensation	(22)	(8)	(23)
Depreciation and amortization	637	717	860
Provision for excess and obsolete inventories	0	235	611
Provision for doubtful accounts receivable	15	(122)	525
Change in deferred tax asset net of valuation allowance	(113)	(116)	10,512
Gain on sale of marketable and long term investments, net	(5)	(74)	(103)
Tax on unrealized gains on marketable and long term investments	197	0	0
Other	13	0	0
Changes in assets and liabilities:
Accounts receivable	(1,000)	(759)	1,940
Inventories	(4,281)	(275)	2,908
Other current assets and prepaid expenses	2,604	2,314	1,014
Other long-term assets	(486)	0	0
Accounts payable	1,277	215	(609)
Accrued liabilities	2,970	(2,646)	42
Deferred rent	45	(200)	(62)
Deferred revenue	(895)	(1,208)	(3,537)
Income tax liability	1	(272)	(703)
Net cash provided by (used in) operating activities	(5,168)	(8,059)	41
Cash flows from investing activities:
Acquisition of property and equipment	(751)	(275)	(154)
Disposal of property and equipment	36	0	0
Proceeds from sales of marketable and long-term investments	21,198	42,830	27,914
Proceeds from maturities of marketable investments	47,935	42,505	11,535
Purchase of marketable investments	(63,131)	(87,837)	(53,655)
Net cash provided by (used in) investing activities	5,287	(2,777)	(14,360)
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan	1,360	518	585
Excess tax benefit related to stock-based compensation	22	8	23
Net cash provided by financing activities	1,382	526	608
Net increase (decrease) in cash and cash equivalents	1,501	(10,310)	(13,711)
Cash and cash equivalents at beginning of year	12,519	22,829	36,540
Cash and cash equivalents at end of year	14,020	12,519	22,829
Supplemental and non-cash disclosure of cash flow information:
Cash paid (received) for income taxes	$ (1,345)	$ 272	$ 578

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).