Oh this is fun. Multimedia artist Rune Madsen took the usually-passive act of people watching and made it, well, a lot less passive. Watch how the stream of pedestrian traffic adapts as his buddy rearranges some sidewalk barricades.
Madsen worked on the project with Scott Wayne Indiana, the mischievous fellow who's seen moving the barricades around in the video. [RuneMadsen via Laughing Squid]