but I've seen better. I remember an episode of "Northern Exposure" where Ed was building a catapaut to fling a cow. For humane reasons, they ended up throwing a piano instead. I couldn't tell how far it went but it appeared to fly several hundred yards.

"Scientific American" had an article some time ago about some guys in Pennsyvalia who built their own catapault powerful enough to fling small cars. Dave Barry wrote a column about these guys that was a hoot.

Of course, if you want really powerful catapauts, go visit your friendly neighborhood aircraft carrier. I've been told one of those is powerful enough to fling a car for several miles if you could somehow angle the flight deck high enough. I've seen video of carrier crews launching an old car, both as a catapault test and as a form of entertainment on a long cruise. The car went a long ways (shedding pieces all the while) but not nearly as far as it would've gone had it been launched at an angle to the horizon.