[youtube]http://www.youtube.com/watch?v=S_d-gs0WoUw
This lovely animation, complete with ethereal music, shows all of the asteroids we've discovered since 1980. The pattern of asteroid discovery follows the earth around its orbit because we tend to discover asteroids in parts of the sky that are opposite the sun. There's plenty of other interesting information about the video on its YouTube page.
Via Boing Boing