Notes:
The idea for the non-SSH solutions (e.g. Suppose you
have many 100's of machines at work and they can't
all run ssh, and so you have to use rlogin, etc) is to
have the script "worklogin" on the previous slide
dump the value of $DISPLAY into a file ".xdisplay"
in your home directory. Your .cshrc or .bashrc on
the remote host will pick this up (assuming home dir
is shared via NFS) and then set DISPLAY.
This way any Xapps you start up on the remote box
will come back to you. This has nothing to do with
ssh tunnels and is useful on arbitrary LAN.
Run "who am i" and note that the machine you logged
in from is the last item. You'd have to assume :0