I came across this in a trade journal today:

http://www.adhocelectronics.com/Products/Wireless-Light-Switches

It’s a wireless light switch that requires no batteries – pushing the switch creates mechanical energy, which transmits a radio signal to the reciever that turns the light on or off.  You mount the switch on the wall wherever you want it, and install a little reciever module at the light fixture that recieves the signal.

It’s more expensive than a conventional light switch, but on the other hand eliminating the hard wired connection from the switch to the light fixture will save a lot of time and money on the installation.