Move Cart to Header in Magento
<reference name="header">
<block type="checkout/cart_sidebar" name="topcart_mini" as="topcart" template="checkout/cart/topcart.phtml"/>
/*copy/rename frontend\base\default\template\checkout\cart\sidebar.phtml
in frontend\responsive\default\template\checkout\cart\topcart.phtml
/* this goes in .phtml file */
<?php echo $this->getChildHtml('topcart'); ?>
</reference>