Something

/**
 * Implementation of hook_nodeapi().
 */
function menu_nodeapi($node, $op) {
  if (user_access('administer menu') && isset($node->menu)) {
    $item = $node->menu;
    switch ($op) {
      case 'delete':
        $item['delete'] = TRUE;
        // deliberate no break.
      case 'insert':
        $item['link_path'] = "node/$node->nid";
        // deliberate no break.
      case 'update':
        if (!empty($item['delete'])) {
          menu_link_delete($item);
        }
        else {
          menu_link_save($item);
        }
        break;
    }
  }
}