I saw this stairs video recently but wasn’t really sure what it was about. Then I discovered The Fun Theory - an initiative from Volkswagen.
The idea is to make things fun to change people’s behaviour for the better. They have three examples on the site, but are running a competition for submissions and ideas, with a monetary prize. You can see some of the submitted entries, and vote on them, but I think a jury makes the final decision.
I love, love, love the concept. Thinking outside the box to make life a little bit better.