Using RedTacton-enabled devices, music from an MP3 player in your pocket would pass through your clothing and shoot over your body to headphones in your ears. Instead of fiddling around with a cable to connect your digital camera to your computer, you could transfer pictures just by touching the PC while the camera is around your neck. And since data can pass from one body to another, you could also exchange electronic business cards by shaking hands, trade music files by dancing cheek to cheek, or swap phone numbers just by kissing.
NTT is not the first company to use the human body as a conduit for data... 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'm sure their scientists have considered this, but radio carrier waves don't vary to the same degree as people do. I'm curious how that notoriously unreliable piece of engineering, the human body, will causes glitches in this system.
Take the MP3 scenario mentioned above -- say you're on a treadmill listening to tunes coveyed through your body. What happens as you work up a sweat? Does the resistance of the skin affect the speed or quality of transfer? How about muscle activity?
Or say you're transferring data to a colleague via handshake. Is it possible we'll someday hear comments like, "This download's taking longer than usual -- have you put on some weight?"
I'm also not enthusiastic about a world where computer viruses are transmitted in the same manner as natural viruses. Crowded subways are disturbing enough already.
However, if this technology should work out, there are important health monitoring implications. It wouldn't take much additional effort, for instance, to program an MP3 player to detect cardiac arrhythmias (you'd know you were having V-tach if your iPod cued up "Kickstart My Heart").
Having grappled with EKG leads, and the tracing errors introduced by patient breathing, coughing, sweating, and simple movement, I'm skeptical that these machines could use subtler electric fields for precise tasks like data transfers. I'd love to be proven wrong, though -- for doctors, this technology could give new meaning to the "laying on of hands."