Man, I would have loved to have one of these when I was 13 years old. It's a jet-powered go-kart that reaches speeds of up to 100 km/h (about 62 mph). The owner (who has a website full of other jet-powered projects) says the machine needs a bit of welding and the engine needs tuning, but I suppose if this is your kind of thing you're already going to know how to fix it up. Oh, and it doesn't have brakes:
"No, this is not suitable for children (or even fraidy-cat adults). This is a real-man's gokart — hell it doesn't even have an effective braking system, after all, brakes are for sissies!"
Hmm. Then again, maybe I would have settled for a non-jet engine go-kart, brakes included.