Thought I would add this snippet here. Credits go to nevets from the original at http://drupal.org/node/121662#comment-250362

<?php
if ( ! function_exists('private_get_children') ) {
    function private_get_children($vid, $parent = 0) {
        $items = array();
        $terms = taxonomy_get_tree($vid, $parent, -1, 1);
        foreach ( $terms as $term ) {
            $count = db_result(db_query("SELECT COUNT(nid) FROM {term_node} WHERE tid = %d", $term->tid));
            $items[] =  l($term->name, "taxonomy/term/$term->tid") . " ($count)" . private_get_children($vid, $term->tid);
        }
        if ( count($items) ) {
            return theme('item_list', $items);
        }
    }
}

$vid = 6;  // Set the vid to the vocabulary id of the vocabulary you wish to list the terms from

print private_get_children($vid);
?>