Check out http://groups.google.co.za/group/za-freeriders
I see your from jhb

Hey man, The stunt your asking about is what I call(Since Iwas first to make one), The N-S. Pendulum. It is called this, because the platform(upper Slatted section), is on a pivot, that's about three feet belowe the point your wheels are at, unlike a teeter, in which your wheels are only a few inches above the pivot point. Because of this, if you just ride up it(like a teeter), nothing will happen, so you have to hit the brakes to get your weight past the tipping point!

This results in a very unique feeling, and is best summed up as "The feeling of hitting a "Double"(jump), in slow-mo., without your wheels ever leaveing the ground. I am planing(if I can find the place and the wood), to build one that would start out almost level, and you would enter it from a ladder, and then tip it over, and exit it at almost 90 degrees. This would feel like riding over the entry ramp to a large half pipe.