Revolving Door Generates Energy, Maybe.
Inhabitat shows the Revolution Door from Fluxlab and describes it as "an ingenious sustainable energy harvesting idea that makes you wonder why no one else has thought of it before." Perhaps because a) lots of people have, it was up on halfbakery three years ago, b) more importantly, revolving doors are already hard for some people to use because of the resistance caused by the seals against the side and the weight of the door. Adding a generator adds drag and any more resistance is, well, futile.
Even the creators of the door, in their presentation, think of it as more of a demonstration piece than a real generator saying "By mechanically harvesting a negligible amount of human energy and converting it to a tangible display through the use of a generator, the Revolution Door will directly communicate a single person's contribution to an energy cycle possible through the metabolic relationship between people, technology, and architecture."