List of Directory categories in my template

Hi,

Trying to work out how to list the categories for my directory plugin within my sidebar.php page in my template.

I have this so far:
<?php if(get_post_type() == 'directory_listing') { ?>
<div class="menu-side">
<h2>Directory</h2>
<!--

    <?php some_fnc_here_to_get_categories(); ?>
-->
</div>
<?php } else { blah... ?>

Any ideas?