I drew up a few goodies for Kids Discover Matter. This one dealt with with a new type of liquid that is being used as body armor. It supposedly stays in a liquid form until something strikes it, then instantly hardens, then just as quickly turns back into a liquid.
Watched with our section on chemical reactions. Not exactly what I was looking for since we were focusing on acid / base reactions, but it's what I could find and the kids enjoy Bill. 7F Simple Chemical Reactions (Bill Nye) - YouTube
Here's an activity called Outrageous Ooze. (You might know it as Oobleck.) Includes directions for making the ooze and terrific explanation of colloids and non-Newtonian fluids (if you want to know why it behaves the way it does).
ASPIRE Simple & Comples Machines A series of three immersive activities to be used in middle level science courses. Written using Adobe Flash and Adobe Flash Builder. Students investigate the wedge, lever, inclined plane, pulley, wheel and axle.