Click on the thumbnail for the full picture and then simply right click on the image,
choose "Set as Wallpaper"...and voila!
[1440x900 resolution]

Wallpaper by Liz (for 1280x1024 resolution)...thanks Liz!

Cake or Death Wallpaper (for 1440x900 resolution)
Circle	Neon	Orangey
Operaman	Peace	Filmstar
2.0	Absolutely	Obamasized