This year's badge sports its own API, for your hacking pleasure:
The RFID Strikes Back (Thanks, Aestetix!)
Conference attendees will see first hand where human tracking by commercial and government interests may be headed when they are offered an active RFID conference badge.
Participation in RFID tracking is completely voluntary. If you wish, you can request an electronics-free "unpopulated" badge at registration, or simply remove the battery from your "populated" RFID badge at any time. There will be a limited number of the full-featured badges, so register early to be guaranteed to receive one.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.