This web site can be a good place to take the kids online on a rainy day this summer, or at least get some ideas to entertain them with, where they might learn something along the way. Click on "online story" to go to an interactive story where the user can create a character's name that gets inserted throughout the story.
This site also has several games to play online with a range of difficulty levels and games for different ages. There are also games to print out to play later. The "Science Spells" section is a list of science experiments you can do at home as well. While many can be done by the kids alone, some do need parental help.
For This Week in Geek, I'm Mark Avery.