Here are a few links to other physics teaching websites:

The Physics Education Technology Website has some neat simulation programs; I especially like the one about simple electric circuits.

The Intuitor Creative Learning Website has sections about nurturing gifted children,
good reasons for taking high school physics, a basic physics savvy quiz, a section on chess strategy,
a section on "insultingly stupid movie physics", and many other topics of interest.

The University of Maryland has a fine physics education resource site.

Wolfgang Christian has a fascinating Physlets website with downloadable Java applets which display
moving diagrams and lend themselves to interactive instruction. For more info visit the Applets Resources site.
I particularly liked Melissa Dancy's interactive ray diagram exercises as described in THE PHYSICS TEACHER,Vol 40, November, 2002.

Some simple diagnostic/remedial tests (with solutions) in introductory physics can be found at
Bill Rachinger's site from Monash University in Australia.

C. Rod Nave of Georgia State University has created a web-based Hypercard physics text.
Many thanks to David Wu for correcting that link!

Ron Greene's Physics Illuminations Project (PIP)
is a source of web-based conceptual homework with a score-management system.

Karl Hahn has put together a fine calculus website: (I am very proud to say he is a former student of mine.)

Nick Frasier has recently posted a very extensive Atomic Physics Resource List with links to many relevant websites all around the world.