My sister, Susan, just sent a link to the Piano Staircase, which combines health, music, and fun, three of my favorite things:

Take the stairs instead of the escalator or elevator and feel better” is something we often hear or read in the Sunday papers. Few people actually follow that advice. Can we get more people to take the stairs over the escalator by making it fun to do? See the results here.

The Piano Staircase is from the Fun Theory, which

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.

The site has all sorts of clever ideas, many of which have been realized, and some with videos.