Apple has caved in to public demand and
released Boot Camp - software that will allow an
iMac,
MacBook Pro or
Mac mini system to boot
Windows XP. Of course, the Mac in question has to be Intel based, but it also involves a firmware upgrade and installing a package called Boot Camp Assistant Beta.app into your Utilities folder. Nicely enough, the software does a non-destructive repartitioning of your boot drive, meaning that you don't need unpartitioned disk space beforehand. Very positive results have been reported so far.