Example

$modules = &JModuleHelper::getModules('top');
foreach (array_keys($modules) as $m) {
    echo JModuleHelper::renderModule($modules[$m]);
}

Example output

<table class="contentpaneopen">
  <tr>
    <td valign="top" colspan="2">
    Joomla! 1.5 - 'Experience the Freedom'!. 
    It has never been easier to create your 
    own dynamic site. Manage all your content 
    from the best CMS admin interface and
    in virtually any language you speak.
    </td>
  </tr>
</table>