Several companies have released "wireless mats" - typically about 20cm x 20cm - which can charge devices, but none has taken off because all require devices to have customised components with metal studs which can receive the power.

WildCharge, a Colorado-based company, has released a special backplate for the Morotola RAZR which enables the phone's battery to receive power from its mat, and plans to introduce similar adapters for the iPod Nano and for Blackberry.

Fulton Innovation, another US company, is meanwhile working with Visteon, the car parts manufacturer, on a product which will recharge a phone when it is dropped into a vehicle's cup holder.

Excerpted from the Times Online.