=== modified file includes/theme.inc
--- includes/theme.inc	2010-09-11 23:31:43.000000000 +0530
+++ includes/theme.inc	2010-09-11 23:34:02.000000000 +0530
@@ -1961,6 +1961,14 @@ function theme_username($variables) {
     // $variables['attributes_array']['class'][] = 'myclass';
     $output = '<span' . drupal_attributes($variables['attributes_array']) . '>' . $variables['name'] . $variables['extra'] . '</span>';
   }
+  $account = $variables['account'];
+  if ($account->uid == 0 && isset($account->mail)) {
+    // An Anonymous user has supplied a contact email-id, so it must be included
+    // in the output. The email id is private so including it only in admin pages
+    if(path_is_admin(current_path())){
+      $output .= '<br><span>' . 'Email: ' . $account->mail . '</span>';
+    }
+  }
   return $output;
 }