http://www.pjmccormick.com/next-previous-node-links-drupal-7

o1@jupiter:~/static/jupiter-070314/sites/test-270414.click-monkey.net$ drush dl prev_next
Project prev_next (7.x-1.x-dev) downloaded to /data/disk/o1/static/jupiter-070314/sites/all/modules/prev_next.      [success]
Project prev_next contains 2 modules: prev_next_views, prev_next.
o1@jupiter:~/static/jupiter-070314/sites/test-270414.click-monkey.net$ drush en prev_next
The following extensions will be enabled: prev_next
Do you really want to continue? (y/n): y
prev_next was enabled successfully.                                  [ok]
Prev/Next will index from node 50 downward.                          [status]
o1@jupiter:~/static/jupiter-070314/sites/test-270414.click-monkey.net$ cd ../themes/garland
o1@jupiter:~/static/jupiter-070314/themes/garland$ cat template.php
<?php
function pn_node($node, $mode = 'n') {
  if (!function_exists('prev_next_nid')) {
    return NULL;
  }

  switch($mode) {
    case 'p':
      $n_nid = prev_next_nid($node->nid, 'prev');
        $link_text = 'previous';
      break;

    case 'n':
      $n_nid = prev_next_nid($node->nid, 'next');
      $link_text = 'next';
    break;

    default:
    return NULL;
  }

  if ($n_nid) {
    $n_node = node_load($n_nid);

    switch($n_node->type) {
      case 'article':
        $html = l('"'.$n_node->title .'"', 'node/'.$n_node->nid);
      return $html;
    }
  }
}
o1@jupiter:~/static/jupiter-070314/themes/garland$ cat node.tpl.php
<?php
?>
<div id="node-<?php print $node->nid; ?>" class="<?php print $classes; ?>"<?php print $attributes; ?>>

  <?php print $user_picture; ?>

  <?php print render($title_prefix); ?>
  <?php if (!$page): ?>
    <h2<?php print $title_attributes; ?>><a href="<?php print $node_url; ?>"><?php print $title; ?></a></h2>
  <?php endif; ?>
  <?php print render($title_suffix); ?>

  <?php if ($display_submitted): ?>
    <span class="submitted"><?php print $submitted ?></span>
  <?php endif; ?>

  <div class="content clearfix"<?php print $content_attributes; ?>>
    <?php
      // We hide the comments and links now so that we can render them later.
      hide($content['comments']);
      hide($content['links']);
      print render($content);
    ?>
  </div>

  <div class="clearfix">
    <?php if (!empty($content['links'])): ?>
      <div class="links"><?php print render($content['links']); ?></div>
    <?php endif; ?>

    <?php print render($content['comments']); ?>
  </div>

<?php
Print "Hello, World! yes";
?>

<ul>
  <li><?php print pn_node($node, 'n'); ?></li>
  <li><?php print pn_node($node, 'p'); ?></li>
</ul>
</div>
o1@jupiter:~/static/jupiter-070314/themes/garland$