One guy I met traveling picked up a solar-powered AA battery charger for 5 pounds on eBay UK. I found a nice amount of them with different features on the US one. Seems like it'd be pretty handy and doesn't take up too much space.
It says it has a max throughput of 8 watts. For things that you are charging you can make do with this calculation:
Power = Voltage * Current
8 watts = 5 * X X = 8/5 or 1.6A. Or 5 watts typical (1A in this case). That will allow you to run most devices at the appropriate levels, just keep in mind that starting and stoping devices pulls a lot of juice. For 90 bucks it is something to consider especially if you are going to be out and about in remote areas.