this summer I worked on the campus of Illinois State University. The quad is home to many trees, one of which now holds not one, but two useless ropes. on the end of each rope is a sign. one says pull, the other says push : )
the best part of this task was going out on my lunch break and watching people eagerly run up and pull the rope as hard as they could to no avail, then go to the other side of the tree and try to figure out how to push a rope. (sadly I could not capture any of the attempts, but they were ever so amusing)