I have still not found a better solution than this:http://www.amazon.com/SUNLINQ-400mA-Portable-Solar-Panel/dp/B003M6W7XW
It is very light, and since it outputs normal usb voltage you can connect direct to a phone or ipod, or have the option to use one of those small battery packs to store power. I use a 1800 Mah stick that weighs a couple ounces. The other advantages are that it is flexible and water resistant. I used a hole punch to punch some holes in corners for pack mounting. Every other solar panel I have seen are in a heavier plastic housing, have extra weight/watt, and feel a little more breakable.