You could customize the footer to use more ...
For example, if you are using the Banner for Position 2 in the footer, you will see in the file:
tpl_footer.php
Code:
<!--bof-banner #5 display -->
<?php
if (SHOW_BANNERS_GROUP_SET5 != '' && $banner = zen_banner_exists('dynamic', SHOW_BANNERS_GROUP_SET5)) {
if ($banner->RecordCount() > 0) {
?>
<div id="bannerFive" class="banners"><?php echo zen_display_banner('static', $banner); ?></div>
<?php
}
}
?>
<!--eof-banner #5 display -->
Customizing the code to call that group or others would allow you to have multiple banners in the footer ...