from IEEE computing:
JAPANESE FIRM CREATES FIRST PRACTICAL "HUMAN AREA NETWORK"
Nippon Telegraph and Telephone Corporation (NTT) has developed the first viable Human Area Network (HAN), which uses weak electric fields on the surface of the human body as a medium to enable up to 2 megabytes per second data transfer between devices. Fluctuations in the skin's electrical fields affect an electro-optic crystal in the receiver, changes to which are detected by laser light and converted to a conventional electrical signal. NTT believes its system, RedTacton, is different from similar technologies because it only has to be within 20 centimeters of the skin, rather than in direct contact, and can transmit through clothing or shoes.
According to Tom Zimmerman, creator of a similar technology for IBM, the HAN is an improvement over current wireless technologies such as Bluetooth because users can narrowly limit signal recipients rather than broadcasting to all devices within a given range. Read more