Carnegie Mellon University's Chris Harrison and Microsoft's Dan Morris and Desney Tan have all teamed up to create "Skinput," a system which has you using your own flesh as an input device to play games and music, as well as make calls and browse through mobile interfaces. It's all conceptual at the moment, but the system involves a pico projector that maps various graphics onto your skin, as well as acoustic sensors that can discern where on your flesh you're tapping based on the sound.
It's all pretty wild, but apparently there's quite a bit of acoustic distinction when it comes to where you're tapping on your body — even within a small range. So when would it come in handy? Always. "This approach provides an always-available, naturally-portable, and on-body interactive surface," Chris Harrison wrote on his YouTube page.
Check out more of Skinput in the video above, or get a closer look in the gallery below.