we have set up a Ubuntu workstation with accounts for all the group members. Nxserver from nomachine seems to be what we need, but it is restricted to 2 users. FreeNx isn't easily installable and doesn't seem very reliable. VNC seems to be usable for login to existing open session but not for remote logins on a single workstation.
To be clear, we need a solution to login on a workstation, desktop maintenance isn't necessary at all.