This is possibly old news to many readers, but it's new to me, and still pretty cool. I recently found this cool, visual website: Graffiti Archaeology
. This flash-intensive website hosts an interactive, timelapse display of layers and years of graffiti at 5 San Francisco sites. It's a fascinating way to look at slices in time--photographs taken over the course of 6 years, documenting a kind of urban evolution. What I think is particularly cool is that the constituent photographs are the work of 11 different people who did not set out to collaborate with each other or produce this final project. Yet it still comes together quite nicely. Check it out--it's quite pretty and fun.