Michal Zalewski created this really great Useless Machine — which counts the number of times it has been triggered — and Michal also throws down some back-story about UMs that I didn’t know about.
The original Ultimate Machine is famously attributed to Claude Elwood Shannon, one of the fathers of modern computing. In “Voice Across the Sea”, Arthur C. Clarke describes Shannon’s creation the following way: “Nothing could be simpler. It is merely a small wooden casket, the size and shape of a cigar box, with a single switch on one face. When you throw the switch, there is an angry, purposeful buzzing. The lid slowly rises, and from beneath it emerges a hand. The hand reaches down, turns the switch off and retreats into the box. With the finality of a closing coffin, the lid snaps shut, the buzzing ceases and peace reigns once more. The psychological effect, if you do not know what to expect, is devastating. There is something unspeakably sinister about a machine that does nothing – absolutely nothing – except switch itself off.”