...
use threads;
...
BEGIN {
   $Config{useithreads} or die "Recompile Perl with threads!";
} # end BEGIN
...
   switch($action) {
      case /adminpass(,|$)/ {
         print "Do adminpass ($hostname)\n" if($verbose || $debug);
         $t[++$#t]=threads->new(\&adminpass);
         next;
      } # end case /adminpass/
      case /backup(,|$)/ {
         print "Do backup ($hostname)\n" if($verbose || $debug);
         $t[++$#t]=threads->new(\&backup);
         next;
      } # end case /backup/
      case /buildhosts(,|$)/ {
         print "Do buildhosts ($hostname)\n" if($verbose || $debug);
         $t[++$#t]=threads->new(\&buildhosts);
         next;
      } # end case /buildhosts/
      case /buildhostsdell(,|$)/ {
         print "Do buildhostsdell ($hostname)\n" if($verbose || $debug);
         $t[++$#t]=threads->new(\&buildhostsdell);
         next;
      } # end case /buildhostsdell/
etc...

##</code><code>##


# Loop through all the threads
my $thr;
foreach $thr (threads->list) {
   # Don't join the main thread or ourselves
   if ($thr->tid && !threads::equal($thr, threads->self)) {
      $x=$thr->join;
      print 'TID ' . $thr->tid() . " returned: $x\n" if($verbose || $debug);
   } # end if
} # end foreach

# Exit the script cleanly
exit 0;