Note 6 - Warrants - Warrants Outstanding (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Minimum [Member]
Outstanding, Price Range (in dollars per share)	$ 0.125	$ 0.125
Issued, shares (in shares)	0.35
Issued, Price Range		0.30
Expired, Price Range	$ 0.55	$ 0.25
Outstanding, Price Range (in dollars per share)	$ 0.125	$ 0.125
Exercised, Price Range	0.30
Maximum [Member]
Outstanding, shares (in shares)	1	1
Issued, shares (in shares)		0.75
Issued, Price Range	0.70
Expired, Price Range	$ 0.75	$ 0.75
Outstanding, shares (in shares)	1	1
Exercised, Price Range	0.40
Outstanding, shares (in shares)	13,779,438	8,838,122
Issued, shares (in shares)	5,670,996	9,387,214
Expired, shares (in shares)	(263,545)	(4,582,079)
Outstanding, shares (in shares)	18,036,889	13,643,257
Exercised, shares (in shares)	(1,150,000)