I stumbled upon this video of the Angriest Most Useless Machine.
For those of you not initiated in the ways of Most Useless Machines, it's a device whose only function is to turn itself off. Each time you turn it on a finger pops out and immediately turns itself off.
The trap consists of a 100ft long, 10ft x 10ft corridor, at it's far end is a featurelss door with no handle. Protruding from the wall beside the door is a lever with a sign above it which reads "OPEN" and one below it which reads "CLOSE". Behind the wall sits an ogre, troll or other dim but dangerous creature who has been told to guard this door and stop anyone trying opening it by flipping the lever to CLOSE.
How to play it
The first time a player flips the lever roll 5d6, the resulting number is the PATIENCE of the guarding Ogre, make a note of this number. Each time a player flips the lever to the OPEN position the Ogre flips it back to CLOSE and reduce the Ogre's PATIENCE by 1. When the Ogre's PATIENCE is reduced to 0 it opens the door from his side snaps off the lever and bashes the PC with it before returning through the door and closing it.
Go back the way you came.
Other RPG Uses
Unmodified, the machine would make a perfect Alpha Complex experimental robot...
"Listen up troubleshooters... The Computer, in its infamous wisdom, has granted you temporary security clearance to escort the experimental bot U-SLUS-MASH1N to R&D sector, please make sure that it gets there in one piece... "