Add this code for displaying a category list based on which categories have been most recently updated.

[code lang=”php”]
$cat_array = array();
    $args=array(
      ‘post_type’ => ‘post’,
      ‘post_status’ => ‘publish’,
      ‘posts_per_page’ => 20,
      ‘caller_get_posts’=> 1
      );
    $my_query = null;
    $my_query = new WP_Query($args);
    if( $my_query->have_posts() ) {
      while ($my_query->have_posts()) : $my_query->the_post();
        $cat_args=array(‘orderby’ => ‘none’);
        $cats = wp_get_post_terms( $post->ID ,
‘category’, $cat_args);
        foreach($cats as $cat) {
          $cat_array[$cat->term_id] = $cat->term_id;
        }
      endwhile;
    }
    if ($cat_array) {
      foreach($cat_array as $cat) {
        $category = get_term_by(‘ID’,$cat, ‘category’);
        echo ‘<a href=”‘ . esc_attr(get_term_link($category,
‘category’)) . ‘” title=”‘ . sprintf(__(“View all posts in %s”),
$category->name ) . ‘” ‘ . ‘>’ . $category->name.'</a>’.'<br />’;
      }
    }
    wp_reset_query();
[/code]