you can use this device to make portable devices and medical equippment work more efficiently

 http://www.techpark.net/2008/06/20/skin-tenna-antenna-that-uses-skin-to-transmit-signals/#more-247

The skin tenna has been designed by a group of researchers at Queens university in Belfast, Northern Island. It is a wirless antenna that takes advantage of the wave affect that allows waves to travel along a surface. It allows wireless devices (like pacemakers) to communicate more efficiently with devices anywhere on the body.

Signals are channeled out sideways along the skin by this reflection and the conducting plate. That makes the antenna more efficient, which could double the battery life of body-worn gadgets.