My funky solar backpack has two different solar LED bike lights and cost a total of $45. With the proper connectors, you can power a cell phone from the larger solar light's batteries and PV panel. There's also a second, red, solar LED. The red and white "button" LEDs ($12 @) are powered by button batteries which can be charged in a button battery solar charger ($9). This makes a road-tested, off the shelf, do it yourself solar backpack with three different lighting and battery systems for around $80. That's about half the cost of the commercial solar backpacks and bags now on the market.
The homemade button reads Solar IS Civil Defense and this old, ornery, and dirty fucking solar hippie means it.
Video at http://energyvision.blogspot.com/... and
http://solarray.blogspot.com/... and http://www.youtube.com/...
Parts list:
Solar powered red blinking LED
Solar white LED with detachable panel
Button LED light
Solar Button Battery Charger
There are cables and connectors available for the Solar White LED that can connect it to cell phones, computers, and other devices.
The other buttons on the backpack are
No torture
Impeach Bush/Cheney
Yes, Windmills (for Cape Wind)