FYI to those who are considering playing with FileVault: if you have a large home directory (I admit maybe a little too large) and not too much free space DON'T TURN ON FILEVAULT (unless you are positive you want to use it). I turned on FileVault a few days ago and decided it was nice, but I didn't really need it. However, I quickly discovered that to turn FileVault off you must have enough free space to create a duplicate home directory. While this isn't irreverisble it is more than a little annoying.
As for me... I need to give some serious thought to what I keep in the the home directory.