ok, so i am learning Mac OS X 10.5 Server, and am planning on getting certified eventually. i have the book (Server Essentials, 2nd edition), and am going thru it a second time. I am setting up the server on a 2.66 mac pro. I also have 3 laptops (macbook, macbook pro, and macbook air) now, i plan to make my user accounts mobile, since all the client machines are laptops. but what is the best way to do this? let's say, for example, i log-in one of the machines with user A. i'm still on the network, and leave the computer logged-in, playing itunes. then i go in the other side of the house, and decide to log-in another computer with the same user A. and i decide to play itunes. now i know i will run into a problem when they both try to sync the itunes file that can only be written to by one of the computers, but not both at the same time.