I ran across these rather cool LED lamps at Ikea (having never been in there before):
Unfortunately, they're not for sale online. But I've heard they'll buy one for a Third World kid if you buy one there, all for $20.
It charges three AA nimh 1.2v batteries in a removable battery/solar tray, which you pop out and place in the sun. It takes several hours to recharge, and the light is 350 lux or so; good for a task light. The base is weighted and it has a gooseneck so it's pretty easy to place where you need it. A rather cool feature is that it's easily hacked: some guys at Voltaic Systems made one into an iPad charger. And regular old spade connectors fit into the solar pack so you can use it to power other stuff, or use other power to run the rather nice LED lamp (you'd probably need to step it down to 6v to run off your 12 volt; there's a schematic at the following URL but I'm not enough of an EE to decipher it:
http://blog.spitzenpfeil.org/wordpress/ ... revisited/