So, yes, I'm replying to my own post :) I forgot about good 'ol Parallel::ForkManager. When I dont use the resources for Tk to draw everything, I see the threads starting and pushing data. However, when I ask them to output their contense to the screen, I now only get just one image and the following errors.

./cams-split.pl 
Start Loop 
Start Loop 
Start Loop 
Start Loop 
Zone 1
Zone 2
X Error of failed request:  BadIDChoice (invalid resource ID chosen fo
+r this connection)
  Major opcode of failed request:  55 (X_CreateGC)
  Resource id in failed request:  0x1e00009
  Serial number of failed request:  171
  Current serial number in output stream:  44
X Error of failed request:  BadIDChoice (invalid resource ID chosen fo
+r this connection)
  Major opcode of failed request:  55 (X_CreateGC)
  Resource id in failed request:  0x1e00009
  Serial number of failed request:  177
  Current serial number in output stream:  44
Zone 1
X Error of failed request:  BadIDChoice (invalid resource ID chosen fo
+r this connection)
  Major opcode of failed request:  55 (X_CreateGC)
  Resource id in failed request:  0x1e00009
  Serial number of failed request:  387
  Current serial number in output stream:  44
Zone 1
Zone 1
Zone 1
Zone 1
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I have the debug code in so everyone can tell what is happening better. Here is the current codebase:

#!/usr/bin/perl

# Origional:
# Test program to decode the multipart-replace stream that
# ZoneMinder sends.  It's a hack for this stream only though
# and could be easily improved.  For example we ignore the
# Content-Length.
#
# Mark J Cox, mark@awe.com, February 2006
#
# Added support for multiple "monitors"... still in progress


use Tk;
use Tk::X11Font;
use Tk::JPEG;
use LWP::UserAgent;
use MIME::Base64;
use IO::Socket;
use Parallel::ForkManager;

my $fm = new Parallel::ForkManager(4);

my $host = "someipaddress";
@links=(
  ["/cgi-bin/nph-zms?mode=jpeg&monitor=1&scale=100&maxfps=5&user=web&p
+ass=webuser","1"],
  ["/cgi-bin/nph-zms?mode=jpeg&monitor=2&scale=100&maxfps=5&user=web&p
+ass=webuser","2"],
  ["/cgi-bin/nph-zms?mode=jpeg&monitor=3&scale=100&maxfps=5&user=web&p
+ass=webuser","3"],
  ["/cgi-bin/nph-zms?mode=jpeg&monitor=4&scale=100&maxfps=5&user=web&p
+ass=webuser","4"]
);

my $stop = 0;
my $mw = MainWindow->new(title=>"Cams");
$mw->minsize( qw(640 480));
my $top = $mw->Frame()->pack(-side=>'top');
my $bottom = $mw->Frame()->pack(-side=>'bottom');

my $photo1 = $top->Label()->pack(-side => 'left');
my $photo2 = $top->Label()->pack(-side => 'right');
my $photo3 = $bottom->Label()->pack(-side => 'left');
my $photo4 = $bottom->Label()->pack(-side => 'right');

$mw->Button(-text=>"Stop",-command => sub { $stop=1; })->pack();

foreach my $itemarray (@links) {
   $fm->start and next;
   print "Start Loop \n";
   my ($url,$zone) = @$itemarray;
   getdata($url,$zone);
   $fm->finish;
}
$fm->wait_all_children; 
 

MainLoop;

sub getdata {
    my $url = shift;
    my $id = shift;
    return unless ($stop == 0);
    my $sock = IO::Socket::INET->new(PeerAddr=>$host,Proto=>'tcp',Peer
+Port=>80,);
    return unless defined $sock;
    $sock->autoflush(1);
    print $sock "GET $url HTTP/1.0\r\nHost: $host\r\n\r\n";
    my $status = <$sock>;
    die unless ($status =~ m|HTTP/\S+\s+200|);

    my ($grab,$jpeg,$data,$image,$thisbuf,$lastimage);
    while (my $nread = sysread($sock, $thisbuf, 4096)) {
        $grab .= $thisbuf;
        if ( $grab =~ s/(.*?)\n--ZoneMinderFrame\r\n//s ) {

            $jpeg .= $1;
            $jpeg =~ s/--ZoneMinderFrame\r\n//; # Heh, what a
            $jpeg =~ s/Content-Length: \d+\r\n//; # Nasty little
            $jpeg =~ s/Content-Type: \S+\r\n\r\n//; # Hack

            $data = encode_base64($jpeg);
            undef $jpeg;
            eval {
                $image = $mw->Photo(-format=>"jpeg",-data=>$data);
            };
            undef $data;
            eval {
                print "Zone $id\n";
                if ($id == 1) {
                  $photo1->configure(-image=>$image);
                } elsif ($id == 2 ) {
                  $photo2->configure(-image=>$image);
                } elsif ($id == 3 ) {
                  $photo3->configure(-image=>$image);
                } elsif ($id == 4 ) {
                  $photo4->configure(-image=>$image);
                }
            };
            $lastimage->delete if ($lastimage); #essential as Photo le
+aks!
            $lastimage = $image;
        }
        $jpeg .= $1 if ($grab =~ s/(.*)(?=\n)//s);
        last if $stop;
        $mw->update;
    }
    $stop = 0;
}
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