I have read about this before, and posted an article about a Netherlands revolving door that harnesses kinetic energy, but these concepts are so cool. There is a train station in Tokyo which is part of the “East Japan Railway Company” that harvest kinetic energy as well. They put energy generating floors in, so the kinetic energy generated by the thousands of people in the station every day is actually harnessed and put back into the station. At the moment, the energy is at least used towards powering the signs in the stations, but will be put forth in more and more…
http://www.inhabitat.com/2008/12/11/tokyo-subway-stations-get-piezoelectric-floors/#more-17484