Vista Activation Postpone
The link above is an article on postponing activation of Vista. If done, there should be no reason why it couldn't be used on more than one computer. Whether it's Vista or Mac OS, they're cutting down on only one computer per license.
I ended up purchasing a refurbished Dell after my iBook hit the dust. I'm only running the Home Basic version of Vista without the "eye candy" aero glass and so forth. I enjoy the feel/look of a Mac, but with the controls to do more than a Mac would of course.
It's nice, in that sense. Windows Defender is a lot better than I thought it would be, eventhough I still wouldn't run it without another anti-virus on the computer. It has a good feel to it and has run smoothly the week and half I've had it.
Outside of Windows defender, operating wise I don't feel much difference between this and XP.