ianwestcott:

“This little box has, inside it, some kind of circuitry that harvests WiFi energy out of the air and converts it into electricity. This has been done before, but the Airnergy is able to harvest electricity with a high enough efficiency to make it practically useful: on the CES floor, they were able to charge a BlackBerry from 30% to full in about 90 minutes, using nothing but ambient WiFi signals as a power source.” (via OhGizmo! » Archive » [CES 2010] RCA Airnergy Charger Harvests Electricity From WiFi Signals)