NASA for middle-school students http://www.nasa.gov/audience/forstudents/5-8/features/index.html
National Geographic for Kids http://www.nationalgeographic.com/kids/
a search engine-- just Ask Jeeves a question and he'll answer it http://www.ajkids.com
Tutorials,& games/activities from our math textbook on every topic it covers http://www.classzone.com
An excellent search engine providing every reference imaginable. http://www.refdesk.com
creative recipes for kids for every holiday http://www.kidskuisine.com
math activities and games for every grade level http://www.aaamath.com
online videos and quizzes for every subject at every grade level http://www.brainpop.com