Perpetual Motion Machines in the Yahoo! Directory

Eric's History of Perpetual Motion and Free Energy Machines
Provides a timeline of attempts to solve the holy grail of energy production, beginning in the 13th century.
www.phact.org/e/dennis4.html
Museum of Unworkable Devices
Offers a look at the physics of these proposed devices, profiles of perpetual motion pioneers, and a defense of the quest for perpetual motion.
www.lhup.edu/~dsimanek/museum/unwork.htm
Perpetual Motion
Describes several different models of perpetual motion machines.
www.kilty.com/pmotion.htm
Perpetual Motion Machines
Looks at how to figure out why a particular design won't work.
burtleburtle.net/bob/physics/whythere.html
Perpetual Motion Page, The
Offers several designs.
manor.york.ac.uk/htdocs/perpetual/perpetual.html