+ <?php wp_dropdown_categories(array('hide_empty' => 0, 'name' => 'category_parent', 'orderby' => 'name', 'selected' => $category->parent, 'hierarchical' => true, 'show_option_none' => __('None'))); ?><br />
+ <?php _e('Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.'); ?>