Adafruit IndustriesMintyBoost Kit v3.0 | 14Power Management Development Boards and Kits

Create your own battery-pack and recharger for your iPod/Iphone/GPS/etc… with the MintyBoost Kit v3.0! The MintyBoost Kit has all the electronic parts necessary to build a small and simple, but very powerful, USB charger for your iPod, mp3 player, camera, cell phone, and any other device you can plug into a USB port to charge.
The circuit and the 2 AA batteries (not included) needed to charge can fit in to a small space such as an Altoids gum or mint tint (not included). It will run your iPod for hours, 2.5x more than you would get from a 9V USB charger. The MintyBoost Kit comes unassembled and requires some soldering tools, but it is suitable for beginners even if you’ve never soldered before.