I own one of these solar chargers in black. I paid over twenty dollars for mine about three or four months ago. I was totally impressed. It's actually a really high quality charger!
http://www.ebay.com/itm/30000mAh-Dual-U ... 461f1a94b2I leave it out in the sun all the time. It seems like the battery charges my cell phone every bit as fast as the wall charger though it takes several days to charge the solar battery. I never used it for camping. It's more for emergency use or the big one. So far I only actually used it for real one time when the electricity went out a few weeks ago. It came in handy because I forgot to charge my phone! I'd probably have to own several of them because I'm pretty hard on my phone.
I wonder if they have anything reasonable that will charge a notebook. They didn't last time I looked... It wouldn't do much good for me unless I could also power my wireless modem. A notebook is too big to take camping. I guess that's what they make Dell Venue's for...