use Proc::Queue size => 3;
my $mech = WWW::Mechanize->new(timeout => 90);
while (@urllist) {
    $pid = fork;
    if(defined ($pid) and $pid==0) {
        $mech->get($url);
        print "$mech->content()->as_HTML();
        exit(0);
    }
    1 while waitpid(-1, WNOHANG)>0; # reaps childs
}

##</code><code>##

use Proc::Queue size => 3;
while (@urllist) {
    $pid = fork;
    if(defined ($pid) and $pid==0) {
	my $mech = WWW::Mechanize->new(timeout => 90);
        $mech->get($url);
        print "$mech->content()->as_HTML();
        exit(0);
    }
    1 while waitpid(-1, WNOHANG)>0; # reaps childs
}