Contraption Video

I haven't watched this yet, but I'd like to check it out.
Rube Goldberg style contraption video

Mark Frauenfelder:I've seen a lot of videos where people set up Rube Goldberg systems, but this one is my favorite. I especially like the part where the stool seat spins down and tips a paper towel tube to make a ball roll out and go round a spiral track. Link (Thanks, Rob!)