In order to delay a page redirect with several seconds, I wrote this simple helper

<?php
  use_helper('Javascript');
 
  /**
   * Adds javascript code to delay a page redirect
   *
   * @param string 'module/action' or '@rule' of the action (same argument as url_for())
   * @param int time of delay in seconds. Default = 5
   * @return JavaScript tag for delayed page redirect
   */
  function delayed_redirect($internal_uri, $time = 5)
  {
    sfContext::getInstance()->getResponse()->addJavascript(sfConfig::get('sf_prototype_web_dir').'/js/prototype');
    $code = 'new PeriodicalExecuter(function() { location.href=\''.url_for($internal_uri).'\';}, '.$time.')';
 
    return javascript_tag($code);
  }
 

See http://www.symfony-project.com/book/1_0/07-Inside-the-View-Layer#Adding%20Your%20Own%20Helpers for information on how to add your own helper