For the peeps who don't know why it saves energy: 1st, you charge your phone without electricity from a power plant, obviously, because you are creating electricity by riding. 2nd, it gives you a reason to ride to wherever you want to go, reducing your carbon footprint drastically.
Note: the video is on the last step
Step 1: Get your parts!
1 Bike that you are willing to do some stuff to (every thing is reversible)
1 Small gear that will fit into your chain
1 Small piece of wood
1 Smallish DC motor
1 Cell phone
1 Cell phone charger that you are willing to destroy
A crap load of duct tape
Assorted washers, nuts, and bolts
Hot glue gun
Coke and Dr. Pepper
Good music to listen to
A friend to help you out