Sit on a branch in a tree and saw it off!
your not making this easy for us city folk
I dare you to go find a Tree! haha
Climb in a tree and wait until someone walks by, then just fall out of it. Funniest video wins!! (note: make sure they can't see you when your hiding in the tree)
Go up to a random person of the opposite sex and say that "they're the ugliest person that you've ever seen"