pi@raspberrypi /mnt/winbackup $ nmap -PN -p21 192.168.1.97

Starting Nmap 6.00 ( http://nmap.org ) at 2012-12-20 05:17 EST
Nmap scan report for 192.168.1.97
Host is up (0.0036s latency).
PORT   STATE SERVICE
21/tcp open  ftp

Nmap done: 1 IP address (1 host up) scanned in 1.29 seconds