Here comes the sun. Charge your iPod free from wall outlets or car chargers and use only solar energy doing it. That's what the iSol does. It's a flexible solar panel that's made to connect to Apple's iPod.
And it costs less than $40, so there's not much reason to not be using one of these things. The sun provides us with thousands of times more energy per day than we could even use, so let's make more use of it where we can.