What are good computer games for toddlers and preschoolers?

My son uses the computer at day care, and I’ve not been able to find any of the software for the games that he uses there. Whenever I’m working on my computer at home, he always wants to get on it too, and I would love to have some age appropriate games for him. Do you have any recommendations?
Dad2003 & Jerri-Lynn, my son plays outside all of the time, and he has lots of great toys (both educational and just plain fun) for when we are stuck indoors. Don’t make assumptions about me or my son because when I have to work on my computer he wants to use it too.

You should get one of those leap frog games .. my mother in law got one for my daughter and she isn’t too into it yet .. she is only one .. but i think as she gets oldder it will help for sure.

Jump Start Toddler