Hacking behavior: use the stairs instead of the escalator

Previously submitted ...

http://news.ycombinator.com/item?id=873059

http://news.ycombinator.com/item?id=872759

http://news.ycombinator.com/item?id=871721

What did they do a week after when the novelty wore off?

Certainly giving people a stimulus can reward good behaviour. I recall reading that drivers of (normal engined) cars with a fuel consumption live readout get higher mileage than people driving the same cars without the display.