I think I have heard of OpenSSH for Symbian? Not sure.
I always run VNC (amongst laptop, desktops, and N800) over SSH.
OpenSSH has not been released for Symbian. There's a port of PuTTY, but this is just a plain terminal. It doesn't support port forwarding / SSH tunneling.
Originally Posted by Benson
As for a firewall on the tablet, I really don't understand what that would accomplish in this case.
My bad. I thought that the maemo port of x11vnc couldn't be set to allow connections only from localhost. Maybe I was confusing this to the password settings, which are not supported by the port.