Stockholders' Equity (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2013

Dec. 31, 2012

The following tables summarize the activity of the 2007 Plan for options:

	Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term
Options
Outstanding January 1, 2010		4,913,366		$	3.88		8.1
Granted		2,722,131			2.50
Exercised		(22,316	)		2.56
Forfeited		(2,273,768	)		3.89
Outstanding, December 31, 2010		5,339,413		$	3.18		8.3
Granted		1,934,566			1.71
Exercised		(44,464	)		2.66
Forfeited		(936,533	)		3.07
Outstanding, December 31, 2011		6,292,982		$	2.74		8.0
Granted		852,139			1.22
Exercised		(31,474	)		1.24
Forfeited		(888,035	)		2.91
Outstanding, December 31, 2012		6,225,612		$	2.52		7.4

		Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term
Exercisable, December 31, 2012		4,044,636		$	2.86		6.6
Vested and expected to vest, December 31, 2012		5,963,894		$	2.55		7.3

Assumptions Used to Estimate Fair Value of Stock Option Award Using Black-Scholes Valuation Model

December 31,
	2012		2011		2010
Weighted-average volatility		86%		83%		87%
Risk-free rate		0.79% - 1.18%		0.79% - 2.79%		0.28% - 3.2%
Expected annual dividend yield		-		-		-
Expected weighted-average life, in years		5.9		5.9		6.0

Restricted Stock Activity

The following table summarizes the activity of the 2007 plan for restricted shares:


	Shares			Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
Restricted Shares
Outstanding January 1, 2010		305,316		$	3.36	$	598,419
Granted		35,000			2.67
Vested		(101,899	)		3.29
Forfeited		(127,286	)		3.95
Outstanding, December 31, 2010		111,131		$	2.92	$	470,084
Granted		145,000			1.43
Vested		(123,066	)		2.59
Forfeited		(9,168	)		2.46
Outstanding, December 31, 2011		123,897		$	1.53	$	157,349
Granted		-			-
Vested		(110,564	)		1.53
Forfeited		-			-
Outstanding, December 31, 2012		13,333		$	1.59	$	14,933

Warrants Outstanding Table

At June 30, 2013 and 2012 there were warrants outstanding to purchase 5,620,128 shares of our common stock, respectively. The warrants outstanding as of June 30, 2013 and 2012 were as follows:

Number of Common Shares Underlying Warrants

Issue Date/Exercisable Date

Exercise Price

Expiration Date

100,778

⁽¹⁾

Mar-07/Mar-07

$3.97

Mar-17

705,354

⁽²⁾

Mar-09/Sep-09

$3.00

Sep-14

2,572,775

⁽¹⁾

Jul-09/Jan-10

$2.50

Jan-15

500,000

⁽²⁾

Apr-10/Oct-10

$1.89

Oct-15

1,323,214

⁽²⁾

Jul-10/Jan-11

$1.63

Jan-17

371,423

⁽²⁾

Jun-11/Jun-11

$3.50

Jun-16

46,584

⁽¹⁾

Mar-12/Mar-12

$1.61

Mar-22

5,620,128

Number of Common Shares
Underlying Warrants