frontendConfiguration.class.php

<?php
class frontendConfiguration extends sfApplicationConfiguration
{
        public function configure()
        {
                $this->dispatcher->connect('view.configure_format', array($this, 'configureIPhoneFormat'));
        }
        public function configureIPhoneFormat(sfEvent $event)
        {
                $request = sfContext::getInstance()->getRequest();
                //Exclude IPad, but deliver mobile version to other mobile browsers
                if(preg_match('#^(?!.*iPad).*(Mobile|Jasmine|Symbian|NetFront|BlackBerry|Opera Mini|Opera Mobi).*$#i', $request->getHttpHeader('User-Agent'))){
                $ext = sfContext::getInstance()->getRequest()->getParameter('sf_format');
                if($ext != ""){
                        $event->getSubject()->setExtension('.mobile.'.$ext.'.php');
                }else{
                        $event->getSubject()->setExtension('.mobile.php');
                }

                //Always disable Web debug toolbar in Mobile versions:
                sfConfig::set('sf_web_debug', false);           

    }
  }
}