Solar iPhone charger?

Out of left field comes a solar iPhone dual case/charger.  Although it may be trying to help the environment, this device may lack practicality.  Not only does it take 12 hours to charge, but you kind of have to be in the sunlight to have it charge as well.  Not many people I know have 12 hours to devote to standing outside.  In my mind, it's one of those things that sounds like a great idea, but it's just not very feasible.