Listing Sub-Pages & Sub-Sub-Pages

So it turns out to be a bit easier than I thought:

                <?php

                if ($post->post_parent) {
                    $ancestors=get_post_ancestors($post->ID);
                    $root=count($ancestors)-1;
                    $parent = $ancestors[$root];
                } else {
                    $parent = $post->ID;
                }

                ?>

                <?php $args = array(
                    'depth'        => 0,
                    'date_format'  => get_option('date_format'),
                    'child_of'     => $parent,
                    'title_li'     => __(''),
                    'sort_column'  => 'menu_order, post_title'
                ); ?>


                <ul>

                  <?php wp_list_pages( $args ); ?> 

                </ul>