Gets your actual IP address on a NAT system via whatismyip.com
#!/usr/bin/perl
use strict;
use LWP::Simple;
my @content = get("http://www.whatismyip.com/");
foreach (@content) {
chomp;
print "$1\n" and last if /<TITLE>Your\sip\sis\s(.*)\sWhatIsMyIP.co
+m<\/TITLE>/;
}