Ah, the dreams of going off-grid! More importantly, the ability to re-charge in the field when you’ve forgotten to charge fully before leaving home. AA batteries power my small camera and my field recorder, but my cell phone has a built-in battery.
There are a number of solar-powered chargers out there, and some are reasonably priced. There is, however, something incalculably alluring about finding one of those cheap lawn lighting kits, for say $10, and making your own solar charger. More importantly, it would be nice to begin to do such things with my daughter, so that she has a since of *making* things for herself.
Here’s the simplest DIY version I have been able to find: [[Metacafe video]](http://www.metacafe.com/watch/800000/solar_powered_usb_charger_cheap_and_easy_to_make/).