Dual Boot w/ -->Windows XP and Vista<--Follow

I have Windows Vista on my new PC. I was wondering, is it possible to have both Vista and XP on the same machine, and be able to choose which one that is booted up when I start up the PC? I want to know because if possible, I want to be able to install FFXI on the XP version, and see how the game runs on it. Anyone have a configuration like this???