If Brunton has their way you may never have to buy another pack of batteries ever again. Their Freedom Hybrid Charger carries the equivalent of 1,277 AA batteries and carries enough juice to recharge a phone 3-5 times or an iPod 5-10 times. It can be recharged via USB, your wall outlet, or via Solar Power. Its also water resistant and rubberized so it'll be there whenever and wherever you need power. Link: $70
OtterBox's OtterSpot lets you stack and share wireless chargers
The wireless chargers can charge each other and have 5,000mAh of battery life.