Blast from the past, with some new stuff throw in too! I'm not usually a fan of these lists but this one has some good stuff. I was wondering why K10k wasn't there, but sadly it turns out it finally took its last breath a year ago (after years of inactivity): http://kottke.org/11/10/so-long-kaliber10000 They had one of the best tiling background collections of all.