Heights

I am kinda scared of them (heights). Have heard people say u get this adrenalin rush when u fall (bungee etc) which gives u a high.
I went zipping (if u wanna know what that is, check out flyingfox.com) the other day with RG and a few of his friends. There we zips on a cable, from hill to hill. And it did give me an adrenalin rush (am assuming phatne ko adrenalin rush kehte hai)...
Did i enjoy the feeling...not really. I can say the whole experience was good, but dont particularly see myself getting exhilarated by the "adrenalin rush".
I prefer trekking, arduous treks, where i push my physical limits (without having to jump off the hill).