Synchronizing passwords on multiple computers

My non-profit organization has several locations with 3-7 computers that are used by multiple individuals. I'd like to be able to set up user id's and passwords for each of the individuals on each of the computers. I can use addusers.exe to do this. What I'd like to know is if there is a way to be able to synchronize the id's on the computers so that if a user changes the password on one, it automatically changes on the others. The computers are not on a server, just connected through a router. Can it be done?

Thanks for your input.