<pre>
<?php

	require_once 'app/Mage.php';
	umask(0);
	Mage::app('default');

	function productCallback($args)
	{
		$product = Mage::getModel('catalog/product');
		$product->setData($args['row']);
		echo $args['arg1'] . "\n";
		echo $product->getId()."\n";
		print_r( $product->debug() );
		echo "\n";
	}

	$products = Mage::getModel('catalog/product')->getCollection()
				->addAttributeToSelect('id')
				->addAttributeToSelect(array('meta_keyword','meta_description','meta_title'), 'inner');

	Mage::getSingleton('core/resource_iterator')->walk($products->getSelect(), array('productCallback'), array('arg1' => '===='));

?>
</pre>