Hydro Turbine Concept Harvests Electricity From Water Pressure
This little device gets stuck onto the end of a faucet or inserted into an existing water pipe. It's got a little hydroelectric turbine in it, and when water moves through, the turbine spins to charge a battery. You can then plug into the battery to charge stuff. It's not completely free, of course. You're taking advantage of either gravity or a water company pump somewhere, and you'll pay for your electricity with a reduction in water pressure caused by the resistance of the turbine. But hey, if you don't overthink it, it's free [minuscule amounts of] electricity!
Source: ohgizmo.comAdded: 5 March 2009