Talk about going green with the Bicycle Powered Mobile Phone Center. This transporting phone center does not need any AC power in order to juice up exhausted batteries, and the best part is the battery can also be charged whilst the unit is stationary. Here’s an excerpt on how it works.
The one essential thing that a cell phone has that a call shop doesn’t is a battery, so using parts found in a junk yard we created a constantly recharging battery by pedal power. Electricity is generated as the person is traveling to his destination, if the battery runs low at the destination he can drop the kick stand and start cycling in place. Generating electricity from pedaling allows us to travel to the central park, a remote town or a big festival increasing access to inexpensive telephony anywhere. Because this bike is built for the developing world we had to use parts that could be easily found. To generate the electricity we used an old car alternator that sends the electricity generated to a car battery. The electricity stored in the battery is accessed by an old computer UPS to convert the electricity to 110V.
Source: Hacked Gadgets