PsychLab On-Line - Simple shockwave animations let students participate in or recreate classic experiments involving factors such as space perception, reaction time, and conditioning. - http://pantherfile.uwm.edu/johnchay/index.htm
Wadsworth Coglab Online Laboratory - Descriptions of classic experiments. Purchase (of a cd or textbook) required to participate. - http://coglab.wadsworth.com/
The WWW Cognitive Psychology Tutor - Quiz questions and tutorials on topics such as memory, reasoning, and language. - http://teach.psy.uga.edu/CogPsychTutor/
Online Exhibits @ the Exploratorium - Interactive demonstrations in experimental psychology and psychophysics, from the Exploratorium science museum in San Francisco - http://www.exploratorium.edu/exhibits/