How Stuff Works http://www.howstuffworks.com
Secrets to Everyday Stuf http://www.StrangeMatterExhibit.com
Dissect a Frog, etc. http://www.froguts.com/flash_content/index.html
Yuckiest Site http://yucky.discovery.com/flash
Extreme Science http://www.extremescience.net
Science Monster http://www.sciencemonster.com
Bill Nye The Science Guy http://billnye.com
Color Matters http://www.colormatters.com/entercolormatters.html
Cool Science http://www.hhmi.org/coolscience/
Questacon http://www.questacon.edu.au/html/activities.html
Your Weight On Other Planets http://www.exploratorium.edu/ronh/weight/index.html
Simple Machines http://www.edheads.org/activities/simple-machines/index.htm
N.A.S.A. http://www.nasa.gov/audience/forstudents/k-4/index.html
Amazing Space http://amazing-space.stsci.edu/
Journey North/Animal Migrations http://www.learner.org/jnorth/
Infrared Zoo http://coolcosmos.ipac.caltech.edu/image_galleries/ir_zoo
Science Games, etc. http://lhs.berkeley.edu/kids