United States Patent: 6,754,472
Microsoft has been granted a patent for transmitting power and data using the human body. The human body is used as a medium (a bus) to power peripheral devices such as speakers, displays, watches, keyboards, etc. coupled to the body with electrodes. The power source might be a pulsed AC or DC signal.
In addition, data might be transferred from one body to another through skin contact:
"While the above system has been described as a network of devices coupled to a single body it is to be recognized that the network can be extended by connecting multiple bodies through physical contact, e.g., touching hands as part of a handshake. When two or more bodies are connected physically, the linked bodies form one large bus over which power and/or communications signals can be transmitted."