Abseiling
It's a quick way of descending from mountains and it carries its own dangers but, having made serious money from it, I can't say I don't like it in its own right. Safety first, every time; when you are hanging in space and working - trying to screw things into building walls, you have to know you've got your own tested back-up. (See pic right)
Best of all, though, my two boys and I invented a new sport - abre-seiling (you work it out) - in which we get as high as we can up a tree (we have their grandmother's handy beech wood to play in) and then shimmy down; and then prusik, Kleimheist, whatever, back up. The picture above shows Laura in Chamonix, practising the black art. (Truth to tell, she doesn't like it much.)

Gear does fail, safety is paramount and that step backwards into space is gut-wrenching. I once did a 200 foot vertical cliff as smooth as a baby's bottom in North Devon just for the hell of it. The 'step-off' was into space with the sea behind. Awesome.