I was interested to read an entry about a "Do-nothing machine," at the Proceedings of the Athanasius Kircher Society blog. The machine, designed and built by Lawrence Wahlstrom and the feature of a 1954 Popular Mechanics article, "works and works to do nothing well."
I believe I found an excellent example of a Do-nothing Machine in the window of Bern's oldest pharmacy. The video quality is not great--it was night when I filmed it with my little Casio camera. Eli provides some commentary near the end.