Yup done it.
Basically I found it a doddle, just follow the manual and make sure you make a drivers disc as per the instructions.
Don't forget if you are installing XP it has to be a SP2 disc, it won't work from an SP1 one. Oh and if you install an OEM version of XP you'll probably find that it runs fine under Bootcamp but if you also install Parallels or another emulator it will think it's installed on a new computer and need re-authorizing which them M$ won't let you do because OEM's can only be installed on the 1 PC

Although I have got XP running on my Mac I've never once used it as I've always found as good or better alternatives for PC only apps, so much so that I'm seriously considering removing it.