Easiest way to downgrade from Vista?

[apattee]

Is it to delete the partition, repartition the size I want, and then put xp on? Or is there a better faster way?

 

[Bill Gates]

You can reformat the partition in the Windows XP installer if you want the size to remain the same. Otherwise you'll have to go through the Boot Camp assistant, deleting the old partition, and then creating a new one after rebooting.

 

[JPT]

Or you could format the Bootcamp partition with Disk Utility...