If you want to use programs made specifically for Windows that the Mac OS cannot support, you can use Boot Camp, which allows you to install Windows XP Service Pack 2 into your Mac. HOWEVER, you DO need a copy of the Windows XP SP2 (and
only XP SP2, according to Apple anyway) installation if you wish to use Boot Camp. Either the Home Edition or Professional will suffice. More information, including requirements and the Boot Camp installation can be found here:
http://docs.info.apple.com/article.html?artnum=303572