This is a small & simple, but very , mp3 player, camera, cell phone, and just about any other gadget you can plug into a USB port to charge! Charges from 2 AA batteries. This version includes an attached USB to iPod dock connecter for easier carrying/storage for an additional price of $19.00
The charger circuitry and 2 AA batteries fit into an Altoids gum tin, and will run your iPod for hours! 2.5x more than you’d get from a 9V USB charger! You can use rechargable batteries too.
iPod video (tested, using alkaline batteries): 3hrs more video (1 full recharge)
iPod shuffle (not tested): 60 hours more (5 full recharges)
iPod mini (tested w/rechargables): 26 hours more (1.5 full recharges)
This project was developed by ladyada at [http://www.ladyada.net]