diff -urp ../content_taxonomy/content_taxonomy.module content_taxonomy/content_taxonomy.module
--- ../content_taxonomy/content_taxonomy.module	2007-09-03 07:27:11.000000000 -0500
+++ content_taxonomy/content_taxonomy.module	2007-09-12 00:07:55.000000000 -0500
@@ -62,6 +62,7 @@ function content_taxonomy_field_settings
       $form['vocabulary']['vid'] = array(
         '#title' => t('Vocabulary'),
         '#type' => 'select',
+        '#multiple' => TRUE,
         '#default_value' => isset($field['vid']) ? $field['vid'] : 0,
         '#options' => $options_voc,
       );
diff -urp ../content_taxonomy/content_taxonomy_options.module content_taxonomy/content_taxonomy_options.module
--- ../content_taxonomy/content_taxonomy_options.module	2007-08-13 09:17:55.000000000 -0500
+++ content_taxonomy/content_taxonomy_options.module	2007-09-12 00:26:00.000000000 -0500
@@ -175,6 +175,21 @@ function content_taxonomy_options_widget
  * Helper function to create a tree of options
  */
 function content_taxonomy_options_array($vid, $parent = NULL, $depth = 0, $blank_field = TRUE, $show_depth = FALSE) {
+  if (is_array($vid)) {
+    $rv = array();
+    foreach ($vid as $v) {
+      $voc = taxonomy_get_vocabulary($v);
+      $rv[] = "-- {$voc->name} --";
+      $rv += _content_taxonomy_options_array($v, $parent, $depth, false, $show_depth);
+    }
+  }
+  else {
+    $rv = _content_taxonomy_options_array($vid, $parent, $depth, $blank_field, $show_depth);
+  }
+  return $rv;
+}
+
+function _content_taxonomy_options_array($vid, $parent = NULL, $depth = 0, $blank_field = TRUE, $show_depth = FALSE) {
   $options = array();
   
   if ($depth == 1) {