--- template.php	2011-02-20 10:31:10.000000000 -0500
+++ template.php	2011-02-22 15:39:13.421149989 -0500
@@ -213,6 +213,28 @@ function zen_preprocess_html(&$variables
 }
 
 /**
+ * Override or insert variables into page template.
+ *
+ * @param $variables
+ *   An array of variables to pass to the theme template.
+ * @param $hook
+ *   The name of the template being rendered ("page" in this case.)
+ */
+function zen_preprocess_page(&$variables, $hook) {
+  // Add first and last classes to teaser lists
+  if (isset($variables['page']['content']['system_main']['nodes'])) {
+    if ($nids = element_children($variables['page']['content']['system_main']['nodes'])) {
+      $first_nid = reset($nids);
+      $last_nid = end($nids);
+      $first_node = $variables['page']['content']['system_main']['nodes'][$first_nid]['#node'];
+      $first_node->classes_array = array('first');
+      $last_node = $variables['page']['content']['system_main']['nodes'][$last_nid]['#node'];
+      $last_node->classes_array = array('last');
+    }
+  }
+}
+
+/**
  * Override or insert variables into the maintenance page template.
  *
  * @param $variables
@@ -240,6 +262,10 @@ function zen_preprocess_maintenance_page
  *   The name of the template being rendered ("node" in this case.)
  */
 function zen_preprocess_node(&$variables, $hook) {
+  $node = $variables['node'];
+  if (!empty($node->classes_array)) {
+    $variables['classes_array'] = array_merge($variables['classes_array'], $node->classes_array);
+  }
   // Add $unpublished variable.
   $variables['unpublished'] = (!$variables['status']) ? TRUE : FALSE;