Sciencenews.org An excellent source for science news and current event articles.
The Science Spot: Kids Zone A site which lists many great science links.
Great Websites for Kids: Science Another site which has many excellent science links.
KidSites Science Yet one more website which catalogs a bunch of great science websites
YouTube.com Many of the Bill Nye videos I show in class are on YouTube now. All you need to know is the title.
Periodictable.com My absolute favorite Periodic Table website. I bought his excellent book on Amazon.com
Amateur Science Hovercraft Plans This is site which has the free plans to build the Hovercraft I bring to school during my Physics Unit. It costs about $100.00 to build.
KidsAstronomy.com Astronomy for kids, what more can I say.
Physics4Kids A good site which has a lot of physics info. Check out the "motion" section.
Chem4Kids Chemistry info for kids.
Science for Teens A sub page of Kids.gov which has some quality science links. Focus on the "Chemistry", "Physics", and "Space" sections.
PHET Simulations Lots of cool science simulations including "Build An Atom" and "Projectile motion"