#!perl -w
# this version works in Mac OS X
use Time::HiRes 'sleep';
use Mac::Glue ':all';
use strict;

my($f, $vol, $label, @orig, @prop);

$f        = new Mac::Glue 'Finder';
$vol      = $f->prop('startup disk');
$label    = $vol->prop('label_index');

$f->activate;

for my $i (0 .. 32) {
    $label->set(to => $i % 8);
    sleep(.2);
}