Common Stock Purchase Warrants

3 Months Ended

Mar. 31, 2012

Common Stock Purchase Warrants [Abstract]

Common Stock Purchase Warrants

Note 7. Common Stock Purchase Warrants

In connection with various financing transactions we have issued common stock purchase warrants to investors. The following table summarizes warrant activity for the three months ended March 31, 2012:

	Number of Warrants			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Balance outstanding, January 1, 2012		31,649,835		$	0.97		2.8
Warrants issued		—			—		—
Warrants exercised		(2,730	)		0.28		—
Warrants expired		(2,653,080	)		1.04		—
Warrants cancelled		—			—		—
Balance outstanding, March 31, 2012		28,994,025		$	0.96		2.8
Warrants exercisable at March 31, 2012		28,994,025		$	0.96		2.8

	Number of Warrants		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Warrants by Price Range
Warrants priced between $0.50 and $0.64		18,283,513	$	0.59		2.9
Warrants priced between $0.90 and $3.78		10,710,512	$	1.59		2.6
Balance outstanding, March 31, 2012		28,994,025	$	0.96		2.8