Physics Central
Physics Central: Physics in the Bathroom: Ripping Neatly
A great science experiment to demonstrate Newton's First Law of Motion, inertia. There is a step-by-step guide on how to conduct this experiment and links to other sites about inertia.
Other
Fear of Physics: Ball on a String
See Newton's First Law of Motion in action. View a movie that illustrates this principle of physics.
Physics Classroom
The Physics Classroom: Inertia and Mass
This is part of a lesson on Newton's Laws of Motion that focuses on inertia and mass. It restates Newton's first law of motion. The lesson also gives a helpful visual description concerning friction.