Manage users on multiple machine.

I have three mahines on a network. Everytime there is a new user, I have to add new account on each of them.

Is there anyway I can keep the accouts on all three machine synchronized automatically?

You could have a look at Kerberos it may be a bit of over kill.

http://www.google.com/search?hl=en&q=kerberos&spell=1