NTT, the Japanese communications company, has developed a technology called RedTacton, which it claims can send data over the surface of the skin at speeds of up to 2Mbps -- equivalent to a fast broadband data connection....NTT is not the first company to use the human body as a conduit for data: IBM pioneered the field in 1996 with a system that could transfer small amounts of data at very low speeds, and last June, Microsoft was granted a patent for "a method and apparatus for transmitting power and data using the human body."Aside from the sheer coolness factor, the system has several advantages over Bluetooth or similar setups. The most significant is that it is more secure; Bluetooth has a broadcast range of about 10 meters, while RedTaction can only be detected a few centimeters away from the skin, making it much harder to spoof.
But RedTacton is arguably the first practical system because, unlike IBM's or Microsoft's, it doesn't need transmitters to be in direct contact with the skin -- they can be built into gadgets, carried in pockets or bags, and will work within about 20cm of your body. RedTacton doesn't introduce an electric current into the body -- instead, it makes use of the minute electric field that occurs naturally on the surface of every human body. A transmitter attached to a device, such as an MP3 player, uses this field to send data by modulating the field minutely in the same way that a radio carrier wave is modulated to carry information.
I have only one question: will there be any adverse effects to modulating the body's electric field? Probably not, I suppose, but worth looking into. At any rate, read the article and be amazed.