My brothers and I would send the Evel stunt cycle off a ramp at the top of a flight of stairs. It was pretty cool watching it go down like a ski jumper.
That's nothing. In the winter we would build a ramp out of packed snow and ice and jump bales of hay using Flexible Fliers, and in the summer, we jumped over the the little kids in the neigborhood while riding banana bikes over a ramp made from plywood (and broken Flexible Fliers).