Well, we generally use kixtart to install all the programs needed etc. etc.
that gets done by us (only 3 of us)
so we add the clients to the domain and login (at which point the script will start running)
occasionally, not every often though, we just add the client to the domain
the script itself gets run every time a user logs in, no matter what user
that's done because sometimes we add a program, or give something an update
all in all, i think we handle about 40-50 clients per server (1 server each client)

As for the code Shanee posted
I can try that code on monday
see how it works (to be honest, i'm not that much of a kixtart proffesional)

but i kinda have the feeling that the point i'm trying to make is getting missed
i'll explain the current situation and then the situation as we would like to have it.

at the moment, we got 1 .kix file doing everything
setting up printers, installing programs etc, etc
the .kix file is in the folder Netlogon
and all the installers are in Netlogon/Apps/enter program name here

what we like to go for
is that we make a seperate .kix file for each program and put that .kix file into the same folder as that program
for example in Netlogon/Apps/Notepad
and there in would Netlogon/Apps/Notepad/Notepad.kix be

the idea is, is that .kix file in Netlogon will start calling apon all install .kix files
also, that the main .kix file is "smart" enough to take a new .kix file (for example, we added another program into the /Apps folder) by itself, without messing with the main .kix file

the purpose for this
is so that we can just copy the folder of the new program to the other servers and then be done with it, without further messing with the code