Imagine that you are in the middle of the
mountains, and your cell phone battery runs out. You have no way of charging your phone, and you need to make a very urgent
phone call. What do you do? Pick up the hand crank cell phone charger! You will generate 2-8
minutes of battery life for your cell phone, so you will be able to
make that emergency phone call. http://trend-observer.blogspot.com/2007/04/hand-crank-for-cell-phones-lets-you.html