Thank you so much, Thread::Queue does exactly what I need, though the MCE suggestion looks like it would have also worked.

There was a slight oddity that it did not work with SimpleHTTP backgrounded. I had to create my own thread for that and use run().

use threads;
use Thread::Queue;

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

sub handle_request {
    my ($self, $cgi) = @_;
    my $cmd_out;
........
    $command_queue->enqueue($cmd_out);
    my $commands_left=$command_queue->pending();
    myDebug("Threads - there are $commands_left items in the queue");
}


my $server_thread=threads->create(
    sub {
        # Run server but do not background it.
        myDebug("Starting web server\n");
        my $pid = MyServer->new($PORT)->run();
       }
}

while($quit==0) {

    my $commands_left=$command_queue->pending();
    myDebug("Queue runner - There are $commands_left entries in the qu
+eue");
    if($commands_left>0) {
        print "We have commands to process\n";
        $send_command=$command_queue->dequeue();
        print "Sending: $send_command\n";
    } 
    # Sleep so we do not hog the processor
    sleep(1);
}
[download]

All seems to work nicely. :)