We just added an entire spectrum of photovoltaic backpacks & messenger bags by Voltaic systems.
I’m thinking these would be *perfect* at something like Burning Man, Coachella, M3, Fuse-IN / Movement / DEMF, the Muteks, or any other outdoor festival where you need to keep your gadgets charged and there’s not an AC outlet in sight. And (at Burning Man, specifically), you could make all sorts of new friends with your excellent charging-powers as long as the sun’s out.