UNIX and Linux Security Class: Day 1

I am spending this week at the Penn Stater taking a SOS for subsidizing the training. $250 for a Learning Tree class is a steal. So Day 1 as you might expect included introductions and the first couple of chapters. I have already learned about a few tools that I need to look up. Tripwire, Bastille, and some introductory cryptography material. For old school *nix admins, these tools might be old hat, but I am an old school Windows guy who is still relatively new to Linux. As with all classes like this one, I realize how far we have to go for our own security of VoIP systems. Rome wasn't built in a day, but we have a lot of work to do. Job security anyone?