WordPress: Contenido en dos columnas

<?php
    // columna 1
    $args = array("posts_per_page" => 5);
    query_posts($args);
    if (have_posts()) {
    ?>
        <div style="float: left; width: 200px;">
            <?php while (have_posts()) { the_post(); $do_not_duplicate[] = $post->ID; ?>

                <div>
                    <h2><?php the_title(); ?></h2>
                    <div class="the_excerpt"><?php the_excerpt(); ?></div>
                </div>

            <?php } ?>
        </div>
    <?php } ?>

    <?php
    // columna 2
    $args = array("posts_per_page" => 5, "post__not_in" => $do_not_duplicate);
    query_posts($args);
    if (have_posts()) { $i = 0;
    ?>
        <div style="float: right; width: 200px;">
            <?php while (have_posts()) { the_post(); if (in_array($post->ID, $do_not_duplicate)) continue;  ?>

                <div>
                    <h2><?php the_title(); ?></h2>
                    <div class="the_excerpt"><?php the_excerpt(); ?></div>
                </div>

            <?php } ?>
        </div>
    <?php } ?>

    <div style="clear: both"></div>