[ALUG] Restricting ssh logins to certain users (not root)

Is there any simple way of restricting ssh logins to a system to prevent remote root logins? I'd like to do this to add a little more security so that one has to login as a non-root user and *then* su to root (if you want root privileges for some reason). This would mean that an intruder would need to guess/hack two passwords to get root access. -- Chris Green (chris@areti.co.uk) "Never ascribe to malice that which can be explained by incompetence."