Freerice.com - Online quizzes for students. For each answer you get right, the site donates 10 grains of rice through the World Food Programme to help end hunger.
Scratch at MIT - Scratch is a programming language that makes it easy to create your own interactive stories, animations, games, music, and art -- and share your creations with others.
Wired Math - A free math website with games and challenges for students.
Create Your Own Comic - Use Marvel's website to create your own comic strip or comic book
Library Expert Game - Test your knowledge of Library organization and the Dewey Decimal System!