use strict;
use LWP::UserAgent;
use HTTP::Cookies;
use HTTP::Request::Common;

my $cookie_jar = HTTP::Cookies->new( );
my $ua = LWP::UserAgent->new;

$ua->cookie_jar( $cookie_jar );

my $request = GET "http://www.doubleclick.net"; # don't worry, it doesn't get saved :-)

my $response = $ua->request( $request );

$cookie_jar->extract_cookies( $response );

print $cookie_jar->as_string;