So I've got these old P75s with a minimal install of Slack 7 - just enough to boot, get a network connection, start X, and get XDM from a "real" machine.

Only user on the XTerminals is root, with a long, complicated password. All user accounts (xterm1...xtermN) are on the master machine - but if possible I'd like a single username/login to be used on all the XTerms.

How can I lock down the users once they login to the master machine and start a Gnome (or KDE, or BlackBox) session? Ideally I don't want them mucking around with adding/removing panels, applets, changing settings, etc. I've already set passwd to only run for root, but I need to figure out other ways of preventing students (gotta hate the students) from doing things I don't want them to.