Repeat-x Repeat-Y is a site that commissions various artists and illustrators to design 200x200 px patterns to be offered as free desktop wallpapers. It's a pretty brilliant idea and a lot of great illustrators are participating, including Luke Pearson, Art Grootfontein, Jurg Lindenberger, Kim Baise, and Nancy Mungoal (of Pretty Little Thieves) among many, many others.
Admittedly, I'm having a tough time choosing a favorite. Which patterns strike your fancy? Check 'em all out through the link below and let me know!