I do not have a .Mac account, so I don't think iSync will work for me. Plus I have a better idea anyway. On this very iBook I'm typing on now, there are two users (3 but only 2 are mine), one for "personal" use and one for work. Its much easier for me to have two users for many reasons. The catch is my Address Book. I want them to be identical between my two users. I was thinking and could I just make a sym link for the database file of one user to where the other user's database file would be? That way they would actually both be writing to the very same database and not know it, and everything would be sync'd.