So here is a simple project to groom your child into the geek parent you are. Over at Hacked Gadgets Alan pointed out a “how-to” on creating your own USB charger from Lego’s.
The charger uses a Lego motor to generate current which passes through a voltage regulator and off to the USB port. If you don’t already have the Lego motor you can pick them up at target and the voltage regulator at Radio Shack.
When all done, rather then sending your kid to time-out, have them hand-crank and recharge your favorite MP3 player.
Here is a picture of the hand crank with electronics already installed.
Use this diagram to wire together the items to make the hand-crank generator actually work.
Check out this video as proof-positive that you can do it.
For complete details on this project and list of items visit Instructables.
Source: Instructables via Hacked Gadgets