Some cool desktop backgrounds free images:
Mostly black (great desktop background!) 
Image by kevin dooley Mostly black--steal me for your desktop background!
2013 desktop wallpaper_lisa rupp_spring 
Image by Lisa Rupp A new desktop wallpaper! Free for personal use. blogged: blog.lisarupp.com
The Diablo (free desktop wallpaper) 
Image by viZZZual.com When is Diablo III coming? vizzzual.com/2008/05/17