<div class="entry page">

                <h2>Related Posts</h2>

       

                <?php

//for use in the loop, list 5 post titles related to first tag on current post

$tags = wp_get_post_tags($post->ID);

if ($tags) {

  $first_tag = $tags[0]->term_id;

  $args=array(

    'tag__in' => array($first_tag),

    'post__not_in' => array($post->ID),

    'showposts'=>5,

    'caller_get_posts'=>1

   );

  $my_query = new WP_Query($args);

  if( $my_query->have_posts() ) {

    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;

  }

}

?>

</div>