www.tutpup.com
compete in fun, educational games against other kids from all over the World!
www.smartkiddies.com.au
use with children learning mathematical concepts. Children can work at their own rate, be assessed individually and the activities are interactive
http://www.teach42.com/2007/03/06/top-10-free-web-20-sites-for-educators-and-a-few-honorable-mentions/
Top web 2 tools list