In the past few years, we have covered many awesome solar iPhone chargers here. The Continental Solar Backpack is also worth a look. It serves as a backpack, briefcase and messenger bag and has enough compartments and sleeves for all your favorite gadgets.
This backpack lets you recharge your smartphone with sunlight. It is built with water resistant materials. Overload, overcharge, overcurrent, and other safety protections are built-in. The solar panels can charge a tablet in a couple of hours. Like what you see? You can find this project on Kickstarter.