Display All But One Category

I have a three column layout, WP 2.1 running all the latest PHP and MySQL installs. On my right column I have code that displays the 10 most recent posts…

<h1><?php _e("Recent Stories"); ?></h1>
  <?php
    $today = current_time('mysql', 1);
    if ( $recentposts = $wpdb->get_results
    ("SELECT ID, post_title FROM $wpdb->posts
    WHERE post_status = 'publish' AND
    post_type='post' ORDER BY post_date DESC
    LIMIT 10"));
  ?>
    <ul>

  <?php
    foreach ($recentposts as $post) {
    if ($post->post_title == '')
    $post->post_title = sprintf(__('Post #%s'), $post->ID);

    echo "<li><a href='".get_permalink($post->ID)."'>";
    the_title();
    echo '</a></li>';
    }
  ?>
    </ul>

…and it works perfect. However, I also display category 5 in a list below that, and want to exclude it from the query above. How can I do this? I have tried LEFT JOIN with other tables but I just cannot seem to get this to work. I would rather it be exclusive (exclude one category) rather than inclusive (include everything else) because our site is pretty bug and I do not want to list out a comma separated list of all categories TO use, make sense? Any advice would be appreciated.