A lot of bike club folks seem to like jet powered rides. I'm not really sure who all is involved- Doyle, Johny Amerika, Spider, BLBC, Cyclecide, Nimby? Artfag Mafia? I think everybody just works on everything.
A jet-powered wheelchair:.
"Spider's Ride": A VW pancake engine with an airplane propellor and a remote control on one arm, a beer keg pulse jet with a chair and handlebars on the other.
The trebuchet flaming piano fling: