One of the more interesting things that you can do with ssh is set up public and private keys and make it so that transactions between systems require no passwords. The bad thing about this is the obvious. If one of your systems inside get compromised, then your internal network is compromised without any work necessary.
The good thing though is that you can then set up automatic transfers through shell scripts or perl scripts. Either way, it’s definitely has its useful sides too. While this howto is for a Debian installation, it’s really no different at all when it comes to configurations.