Primary Links down the left hand side

I've been using Drupal for some time now, and one of the things I like is the very theme system. Hacking your own theme is very easy. As a hint, the code that render's the primary links is located in the page.tpl.php file. Here's a copy of the relevant code;

<div id="navigation" class="menu <?php if ($primary_links) { print "withprimary"; } if ($secondary_links) { print " withsecondary"; } ?> ">
  <?php if ($primary_links): ?>
    <div id="primary" class="clear-block">
      <?php print theme('menu_links', $primary_links); ?>
    </div>
  <?php endif; ?>

  <?php if (isset($secondary_links)): ?>
    <div id="secondary" class="clear-block">
      <?php print theme('menu_links', $secondary_links); ?>
    </div>
  <?php endif; ?>
</div> <!-- /navigation -->

So I suggest that you might consider hacking your own Zen.

If you go to the block configuration page you can display primary links as a block in the left or right sidebars. I think this might be what you are after, and it won't require any new coding.