Intel AppUp is an online app store for your computer. There are paid and free apps, searchable by topic, available for Windows XP and Windows 7 as well as Moblin.
Intel markets it as an app store for your netbook, but I've found some cool free apps on it, including some for education. I was also happy to see that Angry Birds is now available for Windows. How will I ever get any work done?
There are apps for education, games, reference, sports, books, utilities, and much more. You can also search by paid or free.
This is a good resource for teachers and students looking for free apps for their Windows computers (desktop or notebook.).