NASA
Nasa Space Place: El Space Place
NASA's space science site for kids - en Espanol. Features a wide range of activities, including games, projects, animations, and more. Also contains useful information on basic physics, chemistry, and other natural sciences, offering...
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Newton's Laws of Motion
Lesson plan from the Illinois Institute of Technology that incorporates many demonstrations like pulling a tablecloth from under a place setting, or launching a rocket to show Newton's laws.