A recent post titled 'Japan Railway harvests passenger energy for fun and profit':
"The East Japan Railway Company is getting experimental with ways to make their train stations more environmentally friendly, and have turned to the warm bodies that fill their train seats for part of the solution. They've started installing ticket gates that generate electricity as people pass through them, harvesting the vibrations and pressure that results when people walk through the gates. It's not quite as nefarious as we were hoping for -- we think a bit of time chained to a stationary bicycle inside the train could do a commuter good -- but it still seems a pretty good idea, and we look forward to the results. Testing should last through August 11th, and most indications point to this being a fairly effective manner of getting electricity to where it's needed."
Well, it makes sense - hence Microsoft's patenting of the human skin as receiver - humans are highly electrical!