Alright folks it has been done. Windows XP is now on a Mac. Of course not officially but with a great little tutorial you can do it. The link is here.
The coders narf and blanka were the ones that came up with the solution and basically you have to make a custom XP install disc and then you have to repartition your Mac and put XP on the other half of your hard drive. The tricky part is that XP does not run on EFI. It runs on BIOS which basically complicates the whole thing.
The whole process is about 95% automated but do not try it if you have n00b in blood because you will fail and screw up your Mac.
You will need Windows XP to create the install disc and also the current solution is in beta right now so there are still a lot of kinks to work out. Also, there aren't a lot of drivers but there has been a huge community that has sprung up so hopefully it will get done soon.
Finally though, you can put XP on a Mac! Hip Hip Hooray for narf and blanka