Small example based on php-openid placed in extensions folder:
protected/index.php
require_once($yii);
//OpenId classes import
Yii::$classMap=array(
'Auth_OpenID_FileStore'=>'Auth/OpenID/FileStore.php',
'Auth_OpenID_Consumer'=>'Auth/OpenID/Consumer.php',
'Auth_OpenID_SRegRequest'=>'Auth/OpenID/SReg.php',
'Auth_OpenID_SRegResponse'=>'Auth/OpenID/SReg.php',
);
Yii::createWebApplication($config)->run();
protected/config/main.php
'import'=>array(
'application.extensions.*',
),
dyabr