Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2012

Stockholders' Equity [Abstract]

Weighted average for key assumptions used in determining the fair value of options granted

Expected price volatility	82.71%-82.97%
Risk-free interest rate	0.76%-1.02%
Weighted average expected life in years	6 years
Dividend yield	—

Summary of stock option activity

	Number of Shares			Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value
Outstanding at January 1, 2012		4,553,251		$	3.66
Granted in 2012:
Officers and Directors		223,674			1.85
Others		360,540			2.14
Exercised		(179,178	)		2.29
Forfeitures		(250,741	)		3.26
Outstanding at June 30, 2012		4,707,546		$	3.50	$	6,171,895

Summary of stock options outstanding

Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Aggregate Intrinsic Value
$ 1.00 – 5.00		3,796,301		6.28	$	2.87
$ 5.01 – 10.00		911,245		5.17	$	6.30
		4,707,546					$	6,171,895

Summary of stock options exercisable

Range of Exercise Prices	Number Exercisable		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Aggregate Intrinsic Value
$ 1.00 – 5.00		2,979,443		5.56	$	2.95
$ 5.01 – 10.00		911,245		5.17	$	6.30
		3,890,688					$	4,619,278

Summary of non-vested stock options

Nonvested Shares	Shares			Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
Nonvested at January 1, 2012		786,188
Granted		390,206
Vested		(289,952	)
Forfeited		(69,584	)
Nonvested at June 30, 2012		816,858		$	2.72	$	1,552,617

Summary of warrants outstanding to purchase Common Stock

Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Aggregate Intrinsic Value
$ 0.01 – 5.00		2,291,301		2.45	$	3.80	$	1,987,505