The folks at Volkswagen have been using the public as guinea pigs to see what motivates people to take the steps rather than the escalator, to recycle, and to pick up trash (amongst other activities). The videos show that anything is possible if the participants get a little enjoyment out of it. This is how Volkswagen describes the site:
This site is dedicated to the thought that something as simple as fun is the easiest way to change people’s behaviour for the better. Be it for yourself, for the environment, or for something entirely different, the only thing that matters is that it’s change for the better.
Source: The Fun Theory