Condensed Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities
Net loss	$ (31,987)	$ (9,886)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	2,588	3,525
Depreciation	116	99
Amortization	74
Amortization of investment discount	145
Realized gain on sale of short-term investments	1
Loss on disposal of equipment		13
Changes in operating assets and liabilities:
Accounts receivable	3,631
Inventory	(108)	(531)
Other current and non-current assets	(1,230)	(344)
Accounts payable	(34)	1,514
Accrued liabilities	1,362	(40)
Deferred revenue	(2,962)
Net cash used in operating activities	(28,404)	(5,650)
Cash flows from investing activities
Purchases of property and equipment	(318)	(110)
Payments for intangible assets	(161)	(1,000)
Purchases of marketable securities	(3,508)
Sales and maturities of marketable securities	34,777
Net cash provided by (used in) investing activities	30,790	(1,110)
Cash flows from financing activities
Issuance of common stock, net of costs	5,000	52,745
Exercise of warrants		1,474
Exercise of stock options	1	1,884
Purchase of treasury stock		(44)
Net cash provided by financing activities	5,001	56,059
Increase in cash and cash equivalents	7,387	49,299
Cash and cash equivalents at beginning of the period	21,008	5,165
Cash and cash equivalents at end of the period	28,395	54,464
Non-cash investing and financing activities
Common stock issued to settle severance obligation		$ 860