UK company Solar Technology brings it with this slick multi-device solar charger. iPods, PSPs, and cell phones can all be hooked up to this thing and get full charges. Check out the list of provided connectors here. It has hit the market at $43 a pop, and you can get it here.
I'm picturing attaching this thing to the window on long flights to keep my gear up and running. It will be sweet to have an ipod that won't die 8 hours into a 13 hour flight.