National Geographic for Kids http://www.nationalgeographic.com/kids/
BBC space page Lots of facts and videos of the different planets. Challenge yourself to put the planets in order on the games page. http://www.bbc.co.uk/science/space/
Watch the shadow move across the Earth! It is really fascinating. http://www.fourmilab.ch/cgi-bin/Earth?opt=-p&img=learth.evif
Earth day on-line activities. http://www.sites4teachers.com/links/redirect.php?url=http://www.kidsdomain.com/games
Rain Forest fun! http://www.surfnetkids.com/games/rainforest-ws.htm
Ocean fun! http://www.fi.edu/fellows/fellow8/dec98/intera.html
This is a wonderful site for our weather unit! http://weatherwizkids.com
Magic School site with games. http://www.scholastic.com/magicschoolbus
Rainforest Math- Great site! http://www.rainforestmaths.com/