wp_get_archives tag

Problem solved. I had to install a plugin called ‘Archives for a Category’. This let me add the ‘cat=8’ parameter to the wp_get_archvies tag which for some reason doesn’t normally accept it. I really think wordpress should include it in the codex so people don’t have to bother with a plugin.

Or this in your sidebar.php or php-code widget:

<?php
    $args=array(
      'showposts'=>5,
      'category__in' => array(7,9),
      'caller_get_posts'=>1
    );
    $my_query = new WP_Query($args);
    if( $my_query->have_posts() ) {
      echo '5 recent Posts from category 7 or 9';
      while ($my_query->have_posts()) : $my_query->the_post(); ?>
        <p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
       <?php
      endwhile;
    } //if ($my_query)
  wp_reset_query();  // Restore global post data stomped by the_post().
?>