The Perpetual Motion Machine: The Story of an Invention (Imagining Science) Paperback – May 31, 2011

I'm not sure why this book caught my eye, but it did, and I'm glad. It's a very quick (80 pages) and charmingly written account of one man's attempt to build a perpetual motion machine around 1910. Building in this case consists largely of idly considering how such a "perpet" might change the world, interspersed with the occasional attempt to actually get the thing working. Don't let the 20-odd figures discourage you--give it a try!