The Universal Gadget Wrist Charger sports a 1500mAh 5.5V rechargeable lithium ion battery that comes with nine different adaptors to charge a whole host of portable devices like the iPhone, the PSP, the DS Lite and the DSi/3DS.
The bracelet has LED lights to gauge battery life and weighs only 82 grams. It can be recharged via USB. And since it's connected via cord, Kotaku recommends it for those prone to dropping or misplacing their hardware. Don't think of it as simply a recharge, it's a safety strap.