Make sure you get one that can charge on an overcast day. The small ones usually need direct sunlight for several hours but the larger rolls are fine with cloudy days. If the retailer doesn't know don't get it.
I've got the ice-tech solar charger i9005. http://www.icetechusa.com/catalogue-solar-167464.html
Let me say up front I haven't used it's solar capabilities yet; I just got it a few weeks back and it states you should use it from the plug for 3 charge and discharge cycles before going with the solar. That being said I can make a few comments about it. Construction is very nice, kind of a rubberized material coating the case. I tried to use the supplied cable to charge my cell (razor) and I got an "unauthorized charger" message from the phone. I was able to successfully charge my mp3 player (samsung yp-t9). I does have a bunch of connectors that come with it, but I should point out that all of them connect to the charger via USB. So, I went and bought an AA/AAA usb charger on ebay ($5) so I can charge my rechargable batteries. There is no connector that fits my psp, nor my magellan GPS. The weight isn't bad, but factor in space of connectors, cables, separate AA/AAA charger etc. I'll try and update when I get around to using it's solar capabilities.
I ordered a ac/dc charger and have 2-10w solar cells with a regulator and a 12v battery hooked to it. My thought is to let the 12v charge at all times it can then hook the charger for the rechargeable AA's etc batteries to it as needed. Might check some of the cheaper solar shed lights from Harbor Freight for a cheap set of solar cells batteries to do the same.
I travel a lot and like to stop at the major truck stops on the Interstates. Sometimes they have excellent bargains. I picked up two iSun foldable solar charger panels. Think the price was about $25 each -- current "special" price on Internet is about $65.
Just stored them after returning home but this post has me motivated to test them and perhaps put them to continuous use.
I tried to access the company's web site but got one of those phony link sites. It is/was a Canadian company so if anyone has an update that would be appreciated.
I will post pictures and a pdf of the instructions ASAP.