@Tai Chi,
I saw that a bit ago and loved it, and still love the general concept. (Make people WANT to do good rather than threatening them or whapping them over the head with it.)
The novelty factor kind of bothered me though. I mean, would people continue to have fun with it the 50th time they used the stairs? Or would they tune it out (pun intended) and go back to their usual ways?
The "test" didn't seem long-term enough to be really meaningful. People like novelty.
Still, the video itself is cool...