bine@r2d2:~$ nmap localhost

Starting Nmap 4.20 ( http://insecure.org ) at 2007-07-22 21:54 CEST
Interesting ports on localhost (127.0.0.1):
Not shown: 1694 closed ports
PORT    STATE SERVICE
22/tcp  open  ssh
80/tcp  open  http
631/tcp open  ipp

Nmap finished: 1 IP address (1 host up) scanned in 0.262 seconds