Note 9 - Stockholders' Equity (Details) - Assumptions for valuation of the Waived Warrants associated with May Offering	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Note 9 - Stockholders' Equity (Details) - Assumptions for valuation of the Waived Warrants associated with May Offering [Line Items]
Risk-free interest rate	0.78%
Expected volatility	102.23%
Expected life (in years)	5 years
Expected forfeiture rate	0.00%
Expected dividend yield	0.00%
Waived Warrant [Member] | Minimum [Member]
Note 9 - Stockholders' Equity (Details) - Assumptions for valuation of the Waived Warrants associated with May Offering [Line Items]
Risk-free interest rate	0.50%
Expected volatility	102.86%
Expected life (in years)	3 years 36 days
Waived Warrant [Member] | Maximum [Member]
Note 9 - Stockholders' Equity (Details) - Assumptions for valuation of the Waived Warrants associated with May Offering [Line Items]
Risk-free interest rate	1.03%
Expected volatility	110.88%
Expected life (in years)	4 years 255 days
Minimum [Member]
Note 9 - Stockholders' Equity (Details) - Assumptions for valuation of the Waived Warrants associated with May Offering [Line Items]
Risk-free interest rate	0.85%	1.60%
Expected volatility	83.41%	80.80%
Expected life (in years)	5 years 3 months	5 years
Expected forfeiture rate	5.00%	0.00%
Maximum [Member]
Note 9 - Stockholders' Equity (Details) - Assumptions for valuation of the Waived Warrants associated with May Offering [Line Items]
Risk-free interest rate	1.19%	2.97%
Expected volatility	97.83%	82.30%
Expected life (in years)	6 years	6 years 109 days
Expected forfeiture rate	7.50%	7.50%