I think going nuts with battery operated devices on tour is needlessly complex and I would just use the AC power grid that's along nearly every paved road, but if the gadets are a necessity the dynohub and charger route is the one I'd use. Solar panels won't charge well on a day that isn't sunny or if your route takes you out of direct sunlight into shaded areas. The dynohub will charge all the time you are riding [day/night/rain/shine] and you can use it on your commuter bike at home to get hassle free lighting.

Best of all it saves you from festooning your bike with solar panels to keep your iPod charged!