NetLag: A Webcam World
Netlag is a video of the globe rotating through night and day, except that the entire world is made up of webcam videos. It's a little hard to explain, you really have to see it for yourself. Basically you take hundreds of webcams from all over the world, and build a map out of them. By speeding up the videos from all the webcams, you can watch the world move from night to day.
It's really quite beautiful, check it out.