Charge your devices while just walking to school or work. Assuming it's a sunny day of course. This is one example of a variety of styles. As you can see from the image, there is a flexible, yet durable solar panel embedded on the backpack. This collects the sunlight to charge devices using your USB port that is attached inside the backpack. In addition to being a cool gadget, it is also a pretty high grade backpack as is. The straps are nice and padded, and the materials expands for storage and is very sturdy and durable. Check out more details on this one or browse through a bunch of other styles by clicking the image.