Props to Joe Grand on a great badge design this year. In case you didn't notice, it's basically a freescale development environment in the shape of a badge. You can reprogram at will and flash it back to the original code (included on the DEFCON CD) if you want the original functionality back.

For those who had their heads firmly planted up their ass the entire con, check out the Ninja badges:

http://www.ninjas.org/badges/defcon18.html

Over the top - even managed to cause a DoS on the Aruba wireless gear.