There's a reason they call them FALLS
I have a really bad fear of heights, to the degree that looking at pictures of people near the edge of anything is enough to make me queasy.
This is Victoria Falls in Zimbabwe:
This is some insane guy at the edge of Victoria Falls:
Courtesy of Fark, here's a link to a blog that details many people's pictures/videos of their time in the natural pool at the very edge of Victoria Falls. It looks pretty safe ... but still!