WP add categories and tags for attachments and media objects

gistfile1.txt

//
// add categories for attachments
//
function add_categories_for_attachments() {
  register_taxonomy_for_object_type( 'category', 'attachment' ); 
}
add_action( 'init' , 'add_categories_for_attachments' ); // add tags for attachments function 
function add_tags_for_attachments() {
  register_taxonomy_for_object_type( 'post_tag', 'attachment' ); 
}
add_action( 'init' , 'add_tags_for_attachments' );