InCharge for the Wiimote by Teknocreations
As a Nintendo Wii addict, I can honestly say that nothing spoils your game time more than getting ready to play, only to find out those wireless Wiimotes have dead batteries in them.
Of course, there are several companies that make rechargeable Wiimotes, but those do not last forever. Fortunately, Teknocreations has recently made the InCharge battery pack and charge stand with lithium polymer batteries that can last for hundreds of charges. Each charge is good enough for about 25 hours worth of gameplay, and it can somehow work without any contact with metal of any type.
Unfortunately, I don't have a price for the InCharge by Teknocreations, but it is scheduled to be out soon.
