ActiveState Perl 5.10 on Win32 now bundles threads, threads::shared, and Thread::Queue -- which will do what you want... Here's sample code using threads and Thread::Queue that does what yours does... in a few more lines though.

Dewey

use strict;
use warnings;

use LWP::UserAgent;
use HTTP::Request;
use threads;
use Thread::Queue;

my $MAXTHREADS = 2;  #10;

sub getURL ();
sub endThreads();

my $q = Thread::Queue->new();

my @threadlist = ();
foreach my $y (1..$MAXTHREADS) {
    my $thr = threads->create('getURL');
    push(@threadlist,$thr);
}

open( my $LIST, '<', 'lan.txt' );

while (my $line = <$LIST>) {
    chomp($line);
    $q->enqueue($line);
}

close($LIST);

endThreads();

exit(0);

sub getURL() {

    my $ua = new LWP::UserAgent;
    $ua->timeout(2);
    $ua->agent("Mozilla/6.0");
    my $tid = threads->tid();
    print "started thread $tid\n";
    
    while (my $line = $q->dequeue()) {
        last if lc(substr($line,0,4)) eq 'exit';
        my $url = "http://$line"; #/index.php";
        my $req = HTTP::Request->new('GET',$url);
        my $res = $ua->request($req);
        my $content = $res->content;
        if ($content =~ /ok/) {
            print "<$tid>retrieved content from $line\n";
        }
        else {
            print "<$tid>could not retrieve content from $line\n";
        }
    }
}


sub endThreads() {
    
    foreach my $y (1..$MAXTHREADS) {
        $q->enqueue('EXIT');
    }
    
    while (scalar(@threadlist)) {
        
        my @newthreadlist = ();
        foreach my $thr (@threadlist) {
            if ($thr->is_joinable()) {
                my $tid = $thr->tid();
                $thr->join();
                print "joined thread $tid\n";
            }
            else {
                push(@newthreadlist,$thr);
            }
        }
        @threadlist = @newthreadlist;
        sleep(1) if scalar(@threadlist);
    }
}
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