Joel Cook (aka Frankhats on dump.fm) has added another 1000 icons to his icon page, discussed last fall (new link, new server). [Updated link, 2018]
A recap on the method, from Cook:
Originally I started collecting what I thought could be used as avatars on a web project I was fooling around with (mainly following a tutorial for using pubnub messaging). The idea was to give each new user a random avatar with no username. At the time it was a chat site with nothing hooked up (no history, no system for users, messages just got pushed to any open browser, chaotic), and I was liking the anonymous aspect... but I have moved on to a more fleshed out idea and haven't tried to "finish" the weird hack I was playing with.
Images are not optimized, only forced not to exceed certain dimensions with css. The php script lists every image in the directory and spits it onto the page, and I keep adding to it [currently 2468 images, 145mb --tm]... There are a few broken images and duplicates probably, oh well.
A recap on the theory: it's "image aggregating," but more thoughtfully chosen and, at the same time, Dadaist, than the pedestrian, rote lumping-together of subject matter conjured by that term. It may have loose connections to '60s-'70s conceptual art through a kind of systematic thinking but otherwise it's something different we're wrestling with here. And whereas many institutionally-validated "net artists" make work that resembles what you expect internet art to be, Cook's project squares more with what the net actually is -- vulgar, funny, and beyond the scope of any single artist genius coming out of art school.