Ruby/PHP combo scripts to get your external ip address.

ip.php

<?php
        $ip = $_SERVER['REMOTE_ADDR'];
        print $ip;
?>

ip_checker.rb

require 'open-uri'
open("http://your-own-server/ip.php"){ |f| /([0-9]{1,3}\.){3}[0-9]{1,3}/.match(f.read)[0].to_a[0] }