I'm not afraid of heights, but that made me nauseous. Err, let me re-phrase that, I'm not afraid of heights in enclosed spaces - elevators, skyscrapers, airplanes etc - but is I'm up so high that the wind (or any other weather) could cause me to fall, I'll tense right up, especially if I have to rely on my own coordination and agility (or lack there of) to survive.
I'm glad someone has the stones to do that, but I'm more glad its not me...