Common Stock Purchase Warrants (Tables)

3 Months Ended

Mar. 31, 2013

Common Stock Purchase Warrants [Abstract]

Summary of warrant activity

The following table summarizes warrant activity for the three months ended March 31, 2013:

	Number of Warrants			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Balance outstanding, January 1, 2013		27,386,424		$	0.95		2.1
Warrants issued		0			0.00		0
Warrants exercised		0			0.00		0
Warrants expired		(1,028,550	)		2.00		0
Warrants cancelled		0			0.00		0
Balance outstanding, March 31, 2013		26,357,874		$	0.91		2.0
Warrants exercisable at March 31, 2013		26,357,874		$	0.91		2.0

Summary of warrants outstanding by Price Range

The following table summarizes warrant by exercise price range for the three months ended March 31, 2013:

	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		17,150,014	$	0.59		2.1
Warrants priced between $0.90 and $3.78		9,207,860	$	1.29		1.8
Balance outstanding, March 31, 2013		26,357,874	$	0.91		2.0