I just thought I would mention a couple of things we have been using in our homeschooling that our kids have really enjoyed:
1) Timez Attacks
Multiplication game you can download, in which your kid battles big ogres in underground tunnels (his character uses his multiplication skills to defeat them ; ). The basic download is completely free, although you can pay for different "levels"--basically different scenery, maybe different characters to battle. My kids are happy with the free version.
2) Liberty's Kids
Basically Saturday morning cartoons that teach kids about US history, specifically the American Revolution. I like how they try to get a broad range of perspectives in the episodes, like showing how the British soldiers might feel, and what was going on with Benedict Arnold to make him a traitor. At the moment they are instant downloads available via Netflix, which makes them really convenient.
(If you have been holding off on getting Netflix, they have changed their plans, so now it is even more affordable. We do the plan that is $8 a month, for which we get unlimited instant downloads and one DVD out at a time. If you have the internet connection to support it, it is a fantastic educational support--so many excellent documentaries.)
Please do share your favorite resources here too!