From Wired:
"We can harvest between 5 to 7 watts of energy per footstep that is currently being wasted into the ground," says Claire Price, director of The Facility Architects, the British firm heading up the Pacesetters Project. "And a passing train can generate very useful energy to run signaling or to power lights."
Like solar and wind proponents, vibration harvesters argue that abundant, clean energy is all around us and goes to waste. The challenge is how to store the power efficiently so it provides a continual output even if the vibrations from footsteps or passing trains temporarily taper off."
Energy is abundant, if we can harness the vibrations of feet walking, just think how much power we could generate from say ocean waves, gravity...even earthquakes....how about lightning? Energy is all around, it's just a matter of harnessing and storing it. Battery technology and the power grid are two areas where we should spend more money and make revolutionary improvements that will set us free from fossil fuel.