Researchers at the Korea Advanced Institute of Science and Technology (KAIST) took up the latter approach yesterday by unveiling an iPod nano which communicates with earphones via your body's ability to pump electrical signal. Oh sure, the prototype requires the user to keep a finger pressed to the iPod to close the circuit and there's always risk of a nasty infection after implanting the 10-microwatt/2Mbps chip in your forearm but hey, prototype or not think of the time you'll save not havin...