Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income	$ 466	$ 3,752
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	168	118
Reduction of provision for sales returns and doubtful accounts		(98)
Stock-based compensation	1,959	1,777
Change in the fair value of warrant liability		(2,548)
Changes in operating assets and liabilities:
Accounts receivable	599	(645)
Inventory	(54)	(214)
Prepaid expenses and other current assets	77	(80)
Accounts payable, accrued expenses, and other current liabilities	267	(453)
Net cash provided by operating activities	3,482	1,609
Cash flows from investing activities:
Purchase of equipment	(1,090)	(1,350)
Purchase of investments, net	(2,283)	(2,645)
Net cash used in investing activities	(3,373)	(3,995)
Cash flows from financing activities:
Proceeds from stock options exercised	255	526
Proceeds from exercise of stock warrants		562
Purchase of treasury stock for retirement	(368)
Net cash (used in) provided by financing activities	(113)	1,088
Net decrease in cash and cash equivalents	(4)	(1,298)
Cash and cash equivalents, beginning of period	7,571	7,796
Cash and cash equivalents, end of period	7,567	6,498
Cash paid for interest, net of amount capitalized of $13 thousand in 2012		42
Cash paid for taxes		15
Supplemental non-cash transactions:
Issuance of 476,663 shares of common stock for cashless exercise of 581,895 warrants in 2011.
Conversion of 20 shares of Series B Convertible Preferred Stock for 26,666 shares of common stock in 2011.
Issuance of 49,685 shares of common stock for cashless exercise of 60,000 stock options in 2011.