Using Games to Teach Computers to See
The only way to help computers "see," therefore, is to program them with enough background knowledge so that they can identify objects correctly on sight. But this is harder than it sounds, as it involves massive amounts of time.
Enter Peekaboom, an online game where players try to get others to guess the identity of objects by gradually revealing their shape; the first player to correctly identify the object wins. A graduate student at Carnegie Mellon University wrote the program with an interesting side effect. As players play, they are also programming a computer to identify the objects featured in the game.
Aside from aiding in computer science research, Peekaboom has reportedly become very popular since it was introduced about a month ago. The game is open to all.
Source: Pittsburgh Post-Gazette, unmediated