Index: modules/system/system-behavior.css
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system-behavior.css,v
retrieving revision 1.13
diff -u -r1.13 system-behavior.css
--- modules/system/system-behavior.css	9 Aug 2010 16:58:15 -0000	1.13
+++ modules/system/system-behavior.css	18 Sep 2010 22:24:30 -0000
@@ -303,13 +303,21 @@
  *
  * Used for information required for screen-reader users to understand and use
  * the site where visual display is undesirable. Information provided in this
- * manner should be kept concise, to avoid unnecessary burden on the user. Must
- * not be used for focusable elements (such as links and form elements) as this
- * causes issues for keyboard only or voice recognition users. "!important" is
- * used to prevent unintentional overrides.
+ * manner should be kept concise to avoid unnecessary burden on the user.
+ * "!important" is used to prevent unintentional overrides.
  */
 .element-invisible {
   position: absolute !important;
   clip: rect(1px 1px 1px 1px); /* IE6, IE7 */
   clip: rect(1px, 1px, 1px, 1px);
 }
+
+/**
+ * The .focusable class extends the .element-invisible class to allow the element
+ * to be focusable when navigated to via the keyboard.
+ */
+.element-invisible.focusable:active,
+.element-invisible.focusable:focus {
+  position: static !important;
+  clip: auto;
+}