Make:

Every year, Joe Grand, aka Kingpin, aka The Sultan of Solder, and hardware hacker extraordinaire, designs the badges for Defcon, the annual hacker convention in Vegas. The badges are more than just conference ID badges, they have electronics on-board that do something, and conferees have to figure out what that something is. There's also a Badge Hacking contest, to come up with some cool, outrageous, ingenious hack of the badge. Winner gets an Uber badge, which gets them into Defcons for life.

This year's badge uses the Freescale MC56f8006 DSC (Digital Signal Controller), has an on-board mic, and an RGB LED. Apparently the LED pulses out the morse code of a web address. At that address is a few goodies, like a sketchbook of designs for a badge (a page is seen above), an MP3 song, and most importantly, all of the badge tools, source code, CAD files, etc. According to the discussion on Hack a Day, it appears to do some pretty ingenious stuff (like physically network with other badges).

Previous year's badges:
Defcon 14
Defcon 15
Defcon 16

[Photos via Wired's coverage of the badge.]

More:
DEFCON Badge hacking
DEFCON badge hacking contest (pictures)