I've done it a few times. My favourite is probably abseiling down over the entrance to a cave and having to jump backwards and let loads out (so you swing into the cave, rather than smashing your face on the roof of it). I like freefalling and just snapping the brakes on about 10 foot above the ground. This was particularly amusing when someone I disliked was following me and tried to copy this move, but he wasn't strong enough to grip the rope as hard as required so he got rope burn and landed on his ar53.
