Now that I think about it, I'm shocked that scientists have not thought of this before, but they are finally here: the InStep Nanopower Shoes that create electricity while you walk. Using liquid metal, the shoes can create about 10 to 20 watts of power.
The best part is that you can use that power to charge some of the technological gadgets that you have on you all the time, like your cell phone and iPod.
Researchers Tom Krupkin and J. Ashley Taylor at UW-Madison have been working on the InStep Nanopower Shoes using a process called reverse electrowetting.
The way these shoes work is simple: liquid metal is stored in pouches located in the heel and sole of the shoe and as you walk, you start pumping nano-sized drops of the metal through tiny channels, creating electricity. The electricity is stored in a battery at the center of the shoe, which you can then use to charge whatever you may need.