Great word skipvia! I broke my arm due to this when I was 13 because my sister and I decided that if you looped the loose end of the dog lead (attached to a wire running between two trees) around and clipped it to itself, it made a great swing.
Good story! Mine involved jumping over chairs (backs and all) lined up in a row, each time making it trickier by adding another one to the lineup. Eventually, of course, it'll be one chair too many. I think I was able to clear four of them before visiting the emergency room. Ahh, college.