Checkout Goal Zero Adventure Kit

I bought 2, one for my wife and I. It's definitely heavier than 8 ounces, but packs alot of versatility for me. It can charge by USB cable any device that has a car adapter, and can charge 4 AA or 4 AAA batteries. I currently use it to charge my smartphone and headlamp and gps. It has loops on the corners which allow us to mount them to the top of our packs, that way we can charge while hiking (depending on weather).

Can usually be found for $100-140 sometimes less on ebay.

Also,
Powerfilm makes several charging panels that are in the 4-6 ounce range. They are getting pretty good reviews, however I do not own one.
Powerfilm USB + AA charger
or
Powerfilm AA charger

Steve