plugins[panels][layouts] = layoutplugin

<?php

/**
 * Implementation of hook_panels_layouts().
 */
function erdfisch_ef_twocol_60_40_panels_layouts() {
  $items['ef_twocol_60_40'] = array(
    'title' => t('EF twocol 60_40'), // Name
    'icon' => 'ef_twocol_60_40.png', // Preview
    'theme' => 'ef_twocol_60_40', // Template
    'css' => 'ef_twocol_60_40.css', // Stylesheet
    // Regionen.
    'panels' => array(
      'left' => t('Left column'),
      'right' => t('Right column'),
    ),
  );

  return $items;
}

?>

/* $Id: twocol.css,v 1.1.2.1 2008/12/16 21:27:58 merlinofchaos Exp $ */

.panel-2col {
/*  overflow: hidden;  */
}

.panel-2col .panel-col-first {
  float: left;
  width: 60%;
}
* html .panel-2col .panel-col-first {
  width: 59.9%;
}

.panel-2col .panel-col-first .inside {
  margin: 0 .5em 1em 0;
}

.panel-2col .panel-col-last {
  float: left;
  width: 40%;
}
* html .panel-2col .panel-col-last {
  width: 39.9%;
}

.panel-2col .panel-col-last .inside {
  margin: 0 0 1em .5em;
}

#panels-edit-display .panel-pane,
#panels-edit-display .helperclass {
  margin: .5em;
}

.panel-2col .panel-separator {
  margin: 0 0 1em 0;
}

<?php
// $Id: panels-twocol.tpl.php,v 1.1.2.1 2008/12/16 21:27:58 merlinofchaos Exp $
/**
 * @file
 * Template for a 2 column panel layout.
 *
 * This template provides a two column panel display layout, with
 * each column roughly equal in width.
 *
 * Variables:
 * - $id: An optional CSS id to use for the layout.
 * - $content: An array of content, each item in the array is keyed to one
 *   panel of the layout. This layout supports the following sections:
 *   - $content['left']: Content in the left column.
 *   - $content['right']: Content in the right column.
 */
?>
<div class="panel-display panel-2col clear-block" <?php if (!empty($css_id)) { print "id=\"$css_id\""; } ?>>
  <div class="panel-panel panel-col-first">
    <div class="inside"><?php print $content['left']; ?></div>
  </div>

  <div class="panel-panel panel-col-last">
    <div class="inside"><?php print $content['right']; ?></div>
  </div>
</div>