Bushnell Solarwrap Mini Solar Charger: This little guy weighs approx 85 grams and includes a 2200 Mah battery so should have enough grunt to recharge your phone/ebook reader without itself needing recharging from the sun which takes about a day: http://www.bushnell.com/hunting/outdoor-technology/powersync/solarwrap-mini
PS: You could cut it down to just under 80 grams.
You can also use it to recharge a couple of AAA batteries for your Fenix HL10 torch or similar with a USB AA/AAA battery charger weighing another 20 grams or so such as this hiking solar charger
See Also: http://www.theultralighthiker.com/mobile-phone-battery-life/
