Propulsion Fans

I'm having difficulty finding propulsion fans but here are three small fans I found:

http://www.safetycentral.com/bapopihefanw.html

http://www.safetycentral.com/bapopihefanw1.html

http://www.spacesavers.com/batteryfan.html?utm_source=GoogleProducts&utm_medium=productfeeds&tum_campaign=Froogle