Maybe someone could start a stair challenge? All the other challenges seem such a good idea when I read them, but I don't ever seem to have willpower to even start attempting them?..
A year ago, I decided that I wouldn't use the lifts at my work any more - and I've taken the stairs every day since. It still tires me out sometimes (4 floors from my locker to my desk - multiple times a day), but these things add up!