Fudzilla: "Some might think that the title is one lengthy typo, as it's usually WiFi that depletes your battery, but we assure you it's not. A company called RCA has managed to devise a great little gadget that will allow your phone to harvest WiFi energy and convert it into electricity, thus charging your mobile phone for free. Yes, you read it right - for free. (Tesla was a genius, but not much of a businessman. sub.ed.)
The device is called Airnergy and while this concept isn't new, this seems to be the first time it's found a practical use. In fact, the Airnergy managed to charge a Blackberry from 30% battery to full battery in 90 minutes, all the while using "free" energy."