Is there a way to setup a SSH welcome banner?
Display it in /opt/etc/profile (among other equally-valid solutions).
My Tomato utilities site: http://multics.minidns.net/blog/articles/tomato_utilities
you can use echo in /jffs/etc/profile or /opt/etc/profile to put anything you want at a session start up. Its not a true ssh banner but its a cheap and easy shortcut to a similar effect