Power you cell phone via the sun.
Step 1: Materials/Tools
You don't need much to get this project up and running. I actually bought everything I needed at Radio Shack, and will provide the SKUs for each item in case you want to do the same.
Solar Cell (I used a 6v 50mA one)
Project Box (I used a 5x2.5x2 and it fits perfectly but any small enclosed box that you can cut holes into will do fine)
12VDC Car Power Outlet Socket
Vecro (or your adhesive of choice)
You will also need a soldering iron (15 watt. SKU: 64-2051B), solder (62/36/2. SKU: 64-013), and something to cut 2 holes in the project box (I didn't have anything available designed specifically to cut holes, but I just used my CRKT knife and it worked fine)