diff -r -u ../drupal-7.x-dev.orig/includes/form.inc ./includes/form.inc
--- ../drupal-7.x-dev.orig/includes/form.inc	2009-09-28 15:16:01 -0500
+++ ./includes/form.inc	2009-09-28 15:17:41 -0500
@@ -1171,6 +1171,10 @@
     $element['#attributes']['disabled'] = 'disabled';
   }
 
+  if (!empty($element['#readonly'])) {
+    $element['#attributes']['readonly'] = 'readonly';
+  }
+
   // Set the element's #value property.
   if (!isset($element['#value']) && !array_key_exists('#value', $element)) {
     $value_callback = !empty($element['#value_callback']) ? $element['#value_callback'] : 'form_type_' . $element['#type'] . '_value';