// Create a script in your Vendors folder called zf_include_path.php with the following statement:
ini_set('include_path', ini_get('include_path').dirname(__FILE__));

// In your action, just do the following, replacing Gdata.php with whatever library you wish to load (i.e. Loader.php):
function myAction() {
     App::import('Vendor', 'zend_include_path');
     App::import('Vendor', 'Zend_Gdata', true, false, 'Zend/Gdata.php');
}

Drop the Zend Framework Library folder into your Vendors folder

Deploy Zend Framework within CakePHP

cakephp

PHP