Check out this green gadget, which charges your mobile phone or any other gadget whilst you walk.
The M2E power uses kinetic energy to produce enough power whilst you are walking or running to charge your mobile or iPod.
M2Es technology, a physics-level breakthrough, dramatically increases the amount of power that can be generated from kinetic energy. The power is produced by using motion-produced electromagnetic fields that are harvested, converted to electrical energy and stored for use in a variety of scalable applications. The application possibilities span handheld, mobile devices to larger power requirements, such as hybrid vehicles and power systems for industrial use.
It seems that this technology is in the early stages of development, and I cant actually find out any details of when this device will be released or how much it will cost.
This certainly would be a useful gadget and a much more user friendly option than some of the Solar gadget chargers available today.