I think this may be the fastest way to get a list of all the directories in a given folder/directory using PHP.
$directories = array_filter(glob('*'), 'is_dir');
..and of course, you can also add a path to it if you need to:
$directories = array_filter(glob($myPath.'*'), 'is_dir');
just brilliant – took some finding on the web but works just fine for what i want for an automatic picture gallery where each event has its own folder of pics