Skinput?

Chris Harrison is a researcher at Carnegie Mellon University and has prototyped a new concept called skinput. Skinput allows users to wear an armband that understands complex motions in one's arm or finger when touched or poked or pinched. When determined they can act as buttons attached to devices like iPods and iPhones or even for playing a game like Tetris... this is also made possible by the armband which can project a graphic on the arm for visual purposes. Insane. No more surfaces to carry when your own body is the platform!