Here is a cheap solar powered charger that you may be able to do yourself. Needing only 10 to 15 minutes to create, the hardest materials you may need to make it are some silicon cells.
The others are sure to be easy to find. You would also need a playing card, solettes, magnets and super glue.
For the record, here are the complete materials you would need to make it happen: a copper tape with adhesive backing, super glue, a couple of playing cards, 4 NdFeB magnets between 1/4″ – 1/2″ diameter, 1/32″ – 1/8″ thick, 4-8 solettes and a few AA rechargeable batteries.
Some optional materials include a schottky diode, an indicator LED and some form of rigid backing such as a scrap piece of 1/8″ thick acrylic.
How to do it? Well you can download a pdf file over here. If not you can check out the video after the jump.