Let's take this one step further, as it will be possible to transmit power wirelessly. Marin Solijacic is featured in this Technology Review article:
In his wireless energy system, explains Soljac,, the base station would fill a space with a low-frequency electromagnetic field in the range of a few megahertz. A gadget would be equipped with a receiver, like the power-harvesting circuits used in RFID tags to collect ambient energy. Soljac's circuit would be designed to resonate at the same frequency as the radiation emitted by the power station. When the device came within a couple of meters of the station, circuitry would absorb the energy, charging the device's battery. The system could even power household electronics like televisions and toasters.This technology gives new meaning to the phrase "always on". There is a company that is developing such a technology. The company, called eCoupled, has many resources, including videos, on their website.