EnOcean is developing micro-power sources that derive energy from ambient conditions including light, vibrations, and temperature differentials.  These little power sources should be enough to power peel-and-stick electronic devices including RF transmitters, sensors and switches.  Deriving power from ambient light or heat could allow a house to be retrofitted with new light-switches, volume nobs, information displays and sensors without re-wiring anything.  There could be one RF transmitter in a lightswitch, and a receiver in the light fixture, and they would be linked wirelessly. 

Additional applications could tie in your house's sound system, climate control, and energy monitoring, again, without any new wires, and without pulling in excess energy.  Right now, EnOcean products are used mostly in industrial applications, monitoring warehouses and the like. But with a few years of research, programmable houses might be a matter of simply picking up a few things at WalMart.

 

Via Engadget and CNET