Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 18324)
+++ wp-admin/includes/media.php	(working copy)
@@ -1087,7 +1087,7 @@
 			'input'      => 'textarea'
 		),
 		'url'          => array(
-			'label'      => __('Link URL'),
+			'label'      => __('Link Image To:'),
 			'input'      => 'html',
 			'html'       => image_link_input_fields($post, get_option('image_default_link_type')),
 			'helps'      => __('Enter a link URL or click above for presets.')