Technically, anything off MSDN is supposed to only be used for developing something, with the exception being one copy of office for personal use. So if you grab Vista, make sure to open notepad and type out "echo Hi World" and save it as hello.bat.

I still have access to MSDN from my HP job, and still use it. It was quite clear that the benefit of it wasn't something that ended when the job did. The handy thing is I also caught the renewal cycle before I left. My MSDN expires January 2011. That should help me keep up my ability to run the few MS products I do, while still not paying MS directly. Only time I have technically paid for a license of Windows out of my own pocket was when I bought a Dell laptop, and gave up on fighting them over a refund. Other then that, I've gotten my Windows and Office copies from their roadshows or other events.