Louis Richards
Mounting the entire /usr directory from the server will provide the desired results. Applications updated on the server are then available imediately to all clients. Of course, this is just one solution.
I know it's possible but have you tried this configuration in a classroom with many obsolete computers where students are supposed to start the same program at the same time? X, OpenOffice.org and other large programs will be loaded over the network and benefits of local disks will be lost. Also, updates of packages on clients are not quite straightforward unless you install only those packages which do not place files into /usr.
Shortcuts could be provided for the users to run the programs through ssh (ssh -X server scribus). These shortcuts would continue to work after an upgrade on the server.
Again, the application server has to be powerful enough to handle many users. It's usually no problem in a company where users don't execute the same commands at the same time but it may be a problem in a classroom. We use both application servers and diskless clusters here but they are dimensioned to a typical workload. It's not that easy to take an ordinary and obsolete PC and turn it into a server for many users. -- A.M.