I've been using the solar bulbs from Nokero www.nokero.com which run 1 AA battery internally. They're fairly simple, affordable and do what they're supposed to do. Nokero also has a small USB panel but I haven't tried those.

and the Joos Orange panel/battery from http://solarjoos.com/ which is a USB charger. I use it to charge my iPhone, 2AA Eneloop charger, and SW radio receiver. Looking for a compact camera that charges via USB.

No issues with either so far and they work as advertised. Of course there's plenty of sunshine out here in Borneo. Unless it rains.

I can't charge my video camera or a laptop, so that's something I'll work on when the need arises.