The "edge effect" is the perfect description for that feeling! I don't feel so alone after reading this thread.
I personally LOVE having that "edge effect" hit me. Adrenaline rushes are the best feeling in the world. It makes me feel all tingly all over my insides.
I'm sitting here at my desk reeling, just from looking at the pictures!
It's almost like you feel like if you get close to the edge, you can't stop yourself from throwing yourself off.
I'm getting sick just talking about it, LOL!