WHYVILLE
Many games and activities. Safe chat area with thousands of kids (and design your own online avatar.) Write for the Whyville times. Free (or $5 for high speed pass.)

HOWTOONS
Comic pages with some GOOD science projects.

SANDLOT SCIENCE
All sorts of optical illusions, some animated, some with JAVA applets. Makes your brain hurt, not just your eyes.

HOW STUFF WORKS
Very interesting website. Hundreds of pictures and articles which explain almost anything you can think of!

INVENTIVE KIDS
Many activities including several games. Find out about inventions and women innovators.

KINETIC CITY
Somewhat fun website from the AAAS science organization. Play "kid science detective" games. Graphics-heavy.

BONUS.COM (Java Required!)
Activities, online games, and links to interesting stuff. Check out HOW IT WORKS, SO STRANGE!, WHAT'S INSIDE?, and NATURAL DISASTERS. Parents: this site includes its own kid-safe internet browser.

INTERESTING DEVICES on the Internet
Peer through Web cameras on mountaintops and in offices. Generate Fractals. Control real robots. Create "A-life" creatures. Interface to real Coke machines???!

KID WIZARD
A story with games, also Science spells, slimy potions

BRAINSWEAT is the "Cool Science" links at 4-KIDS.ORG.
Also check out their CREATURES section.

Chem-4-Kids
Ever wanted to figure out Chemistry? Chem-4-kids is a good introduction. Not all boring. Funny stuff included too. Also a Biology section. Try the Bio Tour and Chem Tour.