Ducksters
Ducksters: Physics for Kids: Simple Machines
Kids learn about the science behind simple machines such as levers, wheels, pulleys, inclined planes, and screws. How they work together to make complex machinery.
PBS
Pbs Learning Media: Cyberchase: Bianca Gets in Gear
Bianca visits a bike shop and learns how bicycle gears work in this Cyberchase video segment. [3:26]
Museum of Science
Science Learning Network: Inventor's Workshop
A short piece on Leonardo da Vinci from the Science Learning Network. Placed here because a) there's a decent drawing of an Archimedes' screw, and b) there's a link to an adequate definition thereof.
Other
Utah Online Services: Rss Workshop
A well-regarded introduction to publishing RSS feeds, from the state of Utah Online Services division. In this workshop, you'll learn how to create, validate, parse, publish, and syndicate your own RSS news channel. The emphasis is on...