Cordless extension cords?  Powerbeam has it covered.  Right now, Powerbeam is perfecting a wireless, laser-based power transfer system that can act as an extension cord to power devices using a line-of-sight system that will send power as far as you need it to go.  The lasers are about the size of pepper flakes, and will transfer tens of watts of power, and in the future could transfer more.

Powerbeam has patented a battery powered safety system on the back end of the product that will stop the laser (which creates a warm feeling where it comes into contact with a person, nothing ray gun-esque here) when someone crosses its path.

Powerbeam estimates that their power transfer system is 12 months out to the consumer market.