Physics Demonstrations Collections:

Links to Physics Demonstrations that have been catalogued by major topic as follows:
Mechanics
Fluid Mechanics
Waves and Oscillations
Thermal Physics
Electricity and Magnetism
Modern Physics

After each link you'll find the resources available: pictures, diagrams, directions, etc.

St. Mary's University in Canada
Excellent website that contains demos with detailed information on how they work, how to perform them, and downloadable videos of each demo.

Physics Demonstrations in Video. Wake Forest University
Very good downloadable videos. All topic areas in the B curriculum are included.

Michigan Technological University
Picture, purpose, description, suggestions about how to present  the demonstration and bibliography.

North Caroline State University
Picture, description, materials and in some cases the setup time.

Arizona State University
Brief descriptions. Most of the demos include pictures..

Brown University
Picture,  purpose, equipment, description and set up time.

U.C. Berkeley
Detailed diagram of the setup.

University of Oregon
Simple diagram with a brief explanation.

Cal Poly Pomona Physics
Principle, sketch of the setup and brief directions.

University of Michigan
Objective, procedure, equipment and setup time.

The University of Iowa
Picture, principle, equipment, procedure, reference and in some cases a short video.
AP Central: Physics Web Guide
The AP Physics Web Guide includes links to demos for every single topic of the AP Physics (B and  C) curriculum.

Easy Demos by Physics Lessons
Easy to set up demos with animated illustrations. Just click on the Demos link on top of the webpage.

Science Demos: Daryl Science
Lots of ideas for demos with clear explannations in all science areas

How Things Work: Demonstrations
Louis Bloomfield. UVA
An excellent pdf file with 373 demos in all areas of physics. Most of the demos require very simple equipment or materials. Each demo includes procedure, explanation and  student follow-ups.

Cool Stuff
A neat collection of demo ideas by Chris Chiaverina, an outstanding physics teacher and former president of AAPT.

Physics with Toys
This website helps teachers learn how to use easily made toys to teach physics concepts in a more concrete way.  Question sheets accompany the toys to guide and test the student's understanding of how these toy-like devices demonstrate specific physics concepts.