I looked into solar chargers recently and came away less than impressed. I was primarily looking for something to charge my iphone on my longer trips. I can't seem to live without listening to music or watching a movie late at night when I can't sleep. The reports I read seem to indicate that solar charging may not quite be there for daily use of devises like the iphone. Especially when you consider the variability of the weather.
Instead I opted for an auxiliary battery pack. I went with the Trent IMP550 which gives my phone and additional 3-4 charges, weights 0.33 lbs, and cost $35 + SH. The down side is this particular unit only works with iphones, ipods, etc. However, all my other battery devices (light and range finder) have light weight user replaceable batteries.