Designing your own sustainable energy charger is cool, but how many people are capable of such a thing? Not many. But many people can buy a good solution, so I did. I bought a handy solar energy based charger. It's very simple and charges all my handheld devices. Good, fast, cheap (in the long run). And very handy on holiday, some place with no electricity or not the right plug.
It's not the same I've bought, but similar:
Solar charged battery