Yes, you can either set up a dual/triple boot, or you can make an image of the XP drive, and then load it into something like VirtualPC or VMWare.
The latter is probably easier overall and doesn't require any rebooting, though it will cause some performance loss.
I have 2 hard drives with XP Media Center and Vista 32-bit installed respectively; dual boot. My wife seems to find a way to need information on XP when I am experimenting with Vista. Is there a way to use a virtual PC to load XP from my hard drive while I am in Vista? And vice versa. Please help.