Oh wow, we used to do that. It works with baseball cards, too. I loved the way it made the bike sound!

We would also turn our bikes upside down and get the wheels going fast and "burn" catalpa beans on them. The catalpa tree has beautiful blooms in the spring, and long "beans" later in the summer, 6 or 8 inches long? Or maybe up to a foot long? I just remember we'd hold the beans to the tires and watch 'em disintigrate!