I am preparing to upgrade to Windows 7 at home, and I am a little leery of it, because if the upgrade doesn't go well, I may end up reinstalling certain software, such as Office 2007. There is a free program called Magical Jelly Bean Key Finder which will find the product keys for many of the Microsoft tools. For example, if I needed to reinstall Vista or Office, I wouldn't have to go find my original product keys. I could just use this program to get that information now. It will also allow me to save or print them automatically. It's a random little tool, but definitely something that I am going to use before I do my upgrade, and it's a free piece of software, which is nice.
Link to download