WordPress plugin for related posts ordered by current category. It's small. It's fast. Really!
Related Posts by Category lists similar posts within any post. As a search string the plugin does not use the title of the article nor weighs the content. In fact the category, which was assigned to the post, serves as the source of accordance.
<?php do_action('related_posts_by_category', args) ?> in your single.php template for display a list of similar posts.
<ul> <?php do_action( 'related_posts_by_category', array( 'orderby' => 'RAND', 'order' => 'DESC', 'limit' => 5, 'echo' => true, 'before' => '<li>', 'inside' => '» ', 'outside' => '', 'after' => '</li>', 'rel' => 'nofollow', 'type' => 'post', 'image' => 'thumbnail', 'message' => 'No matches' ) ) ?> </ul>
Please adjust the parameters accordingly.