Video Encyclopedia of Physics Demonstrations - 600 physics demos, accessed via OhioLINK.

Cornell's Physics Video Demonstration Database

Java Applets, Simulations, Visualizations

Bruce's musical acoustics java applets

Physlets from Davidson College

Merlot's list of physics and astronomy materials
Falstad.com math and physics applets

Wolfram Demonstrations Project

Electric and Magnetic Interactions:  The Movies - Ruth Chabay, CMU

Teaching Electromagnetism Using Advanced Technologies