BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 13,873	$ 14,104
Short-term investments available-for-sale	6,847	4,205
Accounts receivables	1,725	1,965
Unbilled receivables	1,409	1,836
Prepaid expenses	2,411	2,441
Other current assets	177	1,558
Total current assets	26,442	26,109
Property and equipment, net	7,949	6,857
Goodwill	33,141	33,141
Restricted cash	755
Other non-current assets	350	469
Total assets	68,637	66,576
Current liabilities:
Accounts payable	2,959	2,645
Accrued expenses and other current liabilities	4,478	4,528
Current portion of notes payable	7	20
Deferred rent	397	386
Total current liabilities	7,841	7,579
Warrant liability	267	368
Deferred revenue	2,500	2,500
Non-current portion of notes payable	400	300
Deferred rent	3,305	1,980
Total liabilities	14,313	12,727
Commitments and contingences
Stockholders' equity:
Preferred stock, $0.01 par value, 2,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.01 par value, 200,000,000 shares authorized; and 122,568,692 shares issued and 122,113,262 shares outstanding at March 31, 2012 and 117,480,867 shares issued and 117,025,437 shares outstanding at December 31, 2011	1,226	1,175
Additional paid-in capital	391,564	383,948
Accumulated deficit	(336,992)	(329,656)
Treasury stock, 455,430 shares, cost basis	(2,450)	(2,450)
Accumulated other comprehensive income	976	832
Total stockholders' equity	54,324	53,849
Total liabilities and stockholders' equity	$ 68,637	$ 66,576