=== modified file 'uc_node_checkout.module'
--- uc_node_checkout.module	2010-03-18 09:56:24 +0000
+++ uc_node_checkout.module	2010-04-15 07:49:20 +0000
@@ -417,6 +421,11 @@
       if (variable_get('uc_node_checkout_submit_redirect', TRUE) && !user_access('edit any '. $type .' content')) {
         $form['#redirect'] = variable_get('uc_add_item_redirect', 'cart');
       }
+                
+      $form['buttons']['cancel'] = array(
+        '#value' => l(t('Cancel'), $_SERVER['HTTP_REFERER']),
+        '#weight' => 10,
+      );
     }
   }