Skinput is a new input device developed at Carnegie Mellon University in cooperation with Microsoft's research lab in Redmond, Washington. If you think that being able to "hold the Internet in your hand" with the iPhone is cool, you'll like controlling your Internet experience with your skin better.
The Skinput system uses two technologies to turn your biggest organ into a workable input device. Tiny pico projectors display choices onto your forearm, and an acoustic detector in an armband detects the ultralow frequency sounds produced by tapping the skin with your finger.
Take a look at this nicely produced explanatory Skinput video.
Here, the user plays tetris on the palm of his hand.
(Skinput tetris on palm)
Although not quite the same technology, this reminds me of the "readout skin" from John Varley's 1992 novel Steel Beach:
Call me old-fashioned. I'm the only reporter I know who still uses his handwriter except to take notes…I snapped the fingers of my left hand… Three rows of four colored dots appeared on the heel of my left hand. By pressing the dots in different combinations with my fingertips I was able to write the story in shorthand, and watch the loops and lines scrawl themselves on a strip of readout skin on my wrist, just where a suicide would slash himself.
Scroll down for more stories in the same category. (Story submitted 3/2/2010)