Improve your vocabulary (or geography) while you help relieve world hunger:
go to http://www.freerice.com
You can use this site to boost your word power, and also learn vocabulary in French, Spanish, Italian, or German, test your geography knowledge, and practice math. Whenever you answer a question correctly, a donation of 20 grains of rice is made to fight world hunger.
Interested in Space and Astronomy?
Amazing Space: http://amazing-space.stsci.edu/ (Try out “Tonight’s Sky”)
Explore NASA for Kids: http://www.nasa.gov/audience/forstudents/index.html
Experiment with paper airplane design: http://www.bestpaperairplanes.com/
Interested in Science?
Got a Question? Ask A Scientist -- http://askascientist.org/ (and see some green mice!)
(Also a good source for science project ideas)
Art? Try http://www.mos.org/sln/Leonardo/ and explore perspectives
Enjoy the Google Doodles? http://www.google.com/logos/ See Google art shown in other countries around the world.
Look at the amazing sidewalk art of Julian Beever: http://www.julianbeever.net/pave.htm What is “anamorphic illusion”?