configurable_products.php

<?php

ini_set('display_errors',1);
error_reporting(E_ALL^E_STRICT);
 
require_once('app/Mage.php');
Mage::app();

$collection = Mage::getModel('catalog/product')->getCollection();

foreach ($collection as $product) {
    if ($product->isConfigurable()) {
        $usedAttributeIds = $product->getTypeInstance()->getUsedProductAttributeIds();        
        if (count($usedAttributeIds) == 0) {
            var_dump($product->getSku());
        }
    }
}