Well we might seen similar concepts if sci-fi Hollywood movies, but the fact is currently there are companies working on this concept. ETRI an Korean technology company presented its 'body area network technology' during Next Generation Computing Show 2006 held in Korea.
This technology allows data to be transmitted to other devices using human body as a medium. For example, if you have a document file to print in a wrist information device, you just wear the device and touch a printer with the hand, then you would get the printed paper.