Lot of people carry around battery powered electronics such as laptops, camera's and cellphones. One problem with all of these is that you need to constantly be charging them or replacing the batteries. Another interesting characteristic of all of these items are that they move around a lot. For example a cellphone moves and shakes as the user walks.

Why not have a simple mechanism similar to automatic watches where this motion can be used to charge the phone. This doesn't need radical design changes either.. rechargeable AA batteries can have something very small like this embedded inside, or in already common cell phone battery designs.

Sure it won't power the whole unit all the time, but at least extend the battery life considerably. Worse case is that the battery is totally dead and you can shake it until it's charged enough to use it to make a quick emergency call or take that breathtaking view you just discover right when you run out battery power on the camera.

1. Motion Powered Battery
2. ???
3. Long time Battery life