This script has been featured on the following websites with thanks to the wonders of google.
http://pallz.net/port.php
http://www.dunton-green.co.uk/kentinternet/port.php
http://sgnews.totalh.com/portChecker.php
http://www.kmcnally.net/stuff/port.php
http://dm-gwi.co.cc/Parsers/RandomCrap.php
http://x10hosting.com/forums/scripts-3rd-party-apps/100490-php-portcheck.html
Woo =]