Here is very simple way how to use Zend Framework and Yui Php Loader Utility.

Below is code. This helper returns YAHOO_util_Loader object so check docs at http://developer.yahoo.com/yui/phploader/

require_once 'phploader/phploader/loader.php';
require_once 'Zend/View/Helper/Abstract.php';
 
class Loota_View_Helper_PhpYuiLoader extends Zend_View_Helper_Abstract{
	static private $loader;
	public function __construct(){
		if(Loota_View_Helper_phpYuiLoader::$loader === null){
			Loota_View_Helper_phpYuiLoader::$loader = new YAHOO_util_Loader("2.8.0"); 
		}
	}
 
	public function phpYuiLoader(){
		return Loota_View_Helper_phpYuiLoader::$loader;
	}
 
}