Whilst I'm wandering around the internet, having a field day with Firefox add-ons, I come across a site that was just really, really cool. Social Wallpapering. If you haven't checked this site out, I highly recommend you head over there now, and I would say to start in the Abstract Section, because that's where the really cool ones are.

You'll either leave with some really awesome wallpapers, or you might even get some really great inspiration for the next time you decide to crack open photoshop.