Joe Grand did an awesome job on this year’s Defcon badges. There is a LED array allowing custom text to scroll, and there are expansion options like a triple-axis accelerometer, and a 2.4GHz RF tranceiver. The schematics were on the Defcon cdrom, and it is very hacker friendly.
There were five different badges – Goon, Human, Press, Speaker, and Uber. Cutwaway Security has pictures of them all here. Gizmodo also has some good pictures here. Credit to the above picture also goes to Gizmodo.
And here is Joe trying to fix a Human badge. One complaint is that they didn’t have enough human badges for everyone, and I actually knew a bunch of people that didn’t get one.