At some point in the future, our gadgets might not need a battery to operate. Perhaps we will have something like the starter on a car that kicks off heat generation and then a device like the Thermobility WPG-1 wireless power generator would make its own power in a self-sustaining fashion.
Nextreme is talking up the WPG-1 and the thing sounds really cool. It is designed to be maintenance free and power objects that need little power. The wireless power generator provides 3.3, 4.1, or 5.0 Vdc at 15kΩ or higher.
The power generator itself is customizable and the current version is about the size of a golf ball. It uses a heat sink with fins to gather heat and that heat is in turn used to generator power. The device is aimed at powering sensors and other things that have low power demands. Samples of the generator are available now for $495 and there is no word on a commercial use for the device at this time.