Technically, I've broken VM's ToS with this, which specifically prohibits portscanning, but..
Code:
username@fileserver:~$ sudo nmap -sS -P0 -p -1024 <myownip>
Starting Nmap 5.00 ( http://nmap.org ) at 2011-12-30 10:26 GMT
Interesting ports on <myhost> (<myip>):
Not shown: 1023 filtered ports
PORT STATE SERVICE
22/tcp open ssh
Nmap done: 1 IP address (1 host up) scanned in 6.71 seconds
No telnet port open here, and Im on a superhub, firmware V5.5.2R30.
Yes, I know port 22 is open, I specifically opened it.