I'm thinking about building an AMD/cpu system to be used with Ubuntu and WinXP.
My plan was to use a hot-swappable drive as the boot drive. If I wanted to boot WinXP, I'd put that hard disk in the drive bay before powering up. And if I wanted to boot Ubuntu, I'd put the other disk in the drive bay instead.
I don't know how sensitive the motherboard bios will be to using two different disks. (I would get identical disks.)
The advantage of this idea would be to enhance the privacy of the files on the Ubuntu disk. WinXP would never see the Ubuntu disk. (Can you tell that I don't like Microsoft snooping around in my hard drive?)