The TV-B-Gone is a tiny infrared remote that can turn off almost any TV. A while ago, I ported the TV-B-Gone software to the Arduino; for details on the port and how it works see my previous post on the Arduino TV-B-Gone.
Mitch Altman, the inventor of the TV-B-Gone, made some improvements to the code for a weekly TV-B-Gone constructing workshop in San Francisco at Noisebridge. If you're in the San Francisco area and are interested in the TV-B-Gone, you might want to check it out.
The main bug fix in the new version is the European codes will now work (if you ground pin 5). (The problem was a bunch of #ifdefs to fit the codes into the ATtiny's limited memory; taking out the #ifdefs fixed the problems.) Pressing the trigger button during transmission will now restart the codes. The delay between codes was increased, which should make transmission more reliable. The Arduino's processor will now sleep when not transmitting (thanks to ka1kjz). (Unfortunately, the rest of the Arduino components are still draining power, so sleep mode will be more useful with stripped-down Arduino variants.)
Important: the pins have been changed around in the new version (to avoid conflicts with the serial port). Pin 2 is now the trigger switch, Pin 3 is the IR output, and Pin 5 is grounded if you want European codes. If you built an Arduino TV-B-Gone before and want to use the new code, make sure you connect to the right pins.