Parallels Desktop allows you to use virtualization. It\'s pretty damn fast. I\'m glad that the days of emulation are over. Parallels Desktop for OS X basically allows you to install virtually any OS like Linux, BeOS, DOS, Windows 95, etc...
Or you can just use Boot Camp to boot right into Windows XP. A little trick I learned is that, since Boot Camp supplies you with all the appropriate drivers by letting you burn a driver disc, you can just use that driver disc to make Parallels load the best inside OS X.
You need a decent amount of RAM though because you\'ll be literally running two OS\'s natively at the same time.
If you don\'t need to run games you won\'t be as affected by it. But you can only always natively boot into WinXP if you feel the need.