$result = db_query('
  SELECT n.title, n.nid, n.created, n.type as cid, n.uid, n.sticky as name
  FROM {node} n
  LEFT JOIN {forum} f
  ON f.nid = n.nid
  WHERE f.tid = %d
                             
  UNION
                             
  SELECT c.subject, c.nid, c.timestamp, c.cid, c.uid, c.name
  FROM {comments} c
  LEFT JOIN {forum} o
  ON o.nid = c.nid
  WHERE o.tid = %d
                              
  ORDER BY created DESC
  LIMIT 5',
                            
  $taxterm, $taxterm);
        
  while ($row = db_fetch_object($result)) {
    print '<pre>';
    print_r($row);
    print '</pre>';        
  }