Do you guys scan your own servers? How often?
Myself I have a home server (CentOS) and I scan it fairly regularly. About once a month. Especially on your home machines that might get roped into that time where you really needed to move that document to your house so you FTPd it to yourself or you wanted to mess with your something or other.
I discovered, most recently, that I had left VNC on since the last time I tried to connect to it (normally I keep it off and just enable it as needed) I also found that there was an http port opened that I'd forgotten about where I had opened an SSH tunnel to my router. All of this was from a simple nmap scan with a Zenmap GUI. Granted, I set the scan to thorough and just left it alone (for three days >.>) while it scanned, stealth scanned, reverse arp-ed, et cetera.
I also discovered I'm running an NTP server, who knew!