Note 7 - Warrants (Tables)

12 Months Ended

Dec. 31, 2013

Warrants [Abstract]

Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]

	Number of Shares			Price Range
Outstanding as of December 31, 2011		5,077,086		$0.125	–	$ 1.00
Issued		6,398,813	(1)		$0.50
Exercised		—			—
Expired		(2,870,871	)	$0.75	–	$2.00
Outstanding as of December 31, 2012		8,390,741		$0.125	–	$1.00
Issued		3,503,328		$0.25	–	$0.50
Exercised		—			—
Expired		(1,275,298	)	$0.50	–	$1.00
Outstanding as of December 31, 2013		10,618,771		$0.125	–	$1.00

Schedule of Assumptions Used to Determine Fair Value of Warrants [Table Text Block]

	2012			2013
Risk free interest rate	0.15%	–	0.57%	0.15%	–	0.78%
Expected volatility	120%	–	489%	112%	–	262%
Expected dividend yield		—			—
Forfeiture rate		—			—
Expected life in years	0.75	–	5.00	1.00	–	3.00