This script finds your ip address:

#!/usr/bin/perl -wT
use strict;

use POSIX qw(uname);
use IO::Socket;

my $hostname = (uname)[1];

my $ipbin  = gethostbyname($hostname)
    or die "Couldn't resolve $hostname : $!";
my $ip = inet_ntoa($ipbin);


print "$hostname => $ip\n";

=output
cobalt.blakem.com => 64.94.194.149
[download]

Though your question might be about machines with multiple ip addresses.... can't really tell.

-Blake