Starfall.com http://www.starfall.com/
National Geographic for Kids http://www.nationalgeographic.com/kids/
Earobics.com http://www.earobics.com/gamegoo/games/squanky2/squanky2.html
Funbrain http://www.funbrain.com/
CoolMath4Kids http://www.coolmath4kids.com/
Learning.com http://www.learning.com/
Tumblebooks.com http://www.tumblebooks.com/