There is another option, ive never tried it myself as i have no need for xp, but ive read alot of good things about it, but from how it sounds it could use alot of system resources.

The solution would be to run XP in a virtual machine. Instructions

All it is a piece of software that, in other words, runs a computer on your computer. So in essence your running two OS's at the same time on the same machine. But as i said this could potentially cause alot of system resources to be used, but I do not know as ive never test. Just pushing this out as an option. XP will use vista's drivers so it doesnt have to use its own.