index.tpl найти:

<p>{NEWEST_USER}</p>

ниже вставить

<!-- IF LOGGED_IN -->				
	<hr>
    <script type="text/javascript">
    f_list = false;
    function users_today() {
      $('#users_today').toggle();
      if (!f_list) ajax.users_today();
      return false;
    }
    ajax.users_today = function() {
      ajax.exec({
        action  : 'users_today'
      });
    };
    ajax.callback.users_today = function(data){
      $('#users_today td').html(data.html);
      f_list = true;
    };
    </script>
    <span class="clickable" style="margin: 5px 0 4px;" onclick="return users_today()" title="Нажать для просмотра">Пользователи, посетившие ресурс сегодня <img src="/images/pic_i.png"></span>
    <span id="users_today" style="display:none"><table><td><b>...загрузка...</b></td></table></span>	
<!-- ENDIF -->

ajax.php


'users_today'       => array('user'),


function users_today()
    {
        $day = TIMENOW - (date('H', TIMENOW) * 60 * 60) - (date('i', TIMENOW) * 60) - date('s', TIMENOW);
       
        $get_users = DB()->fetch_rowset("SELECT username, user_id, user_rank FROM ". BB_USERS ." WHERE user_session_time > $day AND  user_active = 1 ORDER BY username ");
 
        $visitors = '';
        $user_count = 0;
       
        foreach ($get_users as $row)
        {
            $user_count++;
            $visitors .= profile_url($row) .', ';
        }
       
        $this->response['html'] = '
            <table class="gen">
                <tr>
                    <td>Сегодня зашло '. $user_count .' пользователей</td>
                </tr>
                <tr>
                    <td>'. $visitors .'</td>
                </tr>
            </table>
        ';
    }