Codex Perductum

TV-B-Gone is an awesome little device. It is an infrared keychain fob. When you press a button on the keychain, it emits all the known infrared signals for the "Power-Off" command on many types of televisions. It is available at Think Geek

Engadget also has a great video showing the fob in action in a store with a wall of televisions.

Movie is here.