A battery that can be charged by spinning it on the end of your finger.
This looks like it would be of great benefit to couriers who may have forgotten their mobile phone charger.
We have all had it happen to us at one time or another.
We rush out of the door and the last thing on our mind is that in a couple of hours time our phone will be dead with no way of communicating with our customers.
Well this could well be the solution See here