Don't worry! It's only stuff...

<?xml version="1.0" encoding="UTF-8"?>
<!--
	./app/design/frontend/default/default/layout/local.xml
-->
<layout>
    <!-- 
        catalog view
    -->
    <catalog_category_layered>
        <reference name="content">
            <!-- add category banner -->
            <block type="core/template" name="my.catalog.banner" before="-" template="catalog/layer/my.banner.phtml"/>
        </reference>
    </catalog_category_layered>
</layout>

<?php
$banner = array(
    // root category
    "shop.html"
        => array("lcd.jpg", "http://www.example.com/shop/tv/lcd.html"),

    // tv
    "http://www.example.com/shop/tv/lcd.html"
        => array("led.jpg", "http://www.example.com/shop/tv/led.html"),
    "http://www.example.com/shop/tv/plasma.html"
        => array("hdtv.jpg", "/hdtv")
)
?>

<?php
/*
* banner
* ./app/design/frontend/default/default/template/catalog/layer/my.banner.phtml
*
* v2011-02-08
*/
?>

<?php
include("banner.phtml");

$url = Mage::registry('current_category')->getUrlPath();

//$url = str_replace("shop/", "", $url);
//$url = str_replace(".html", "", $url);

$url = "http://www.EXAMPLE.COM/" . $url;

// view banner if available
if(array_key_exists($url, $banner)): ?>
<div class="block category-banner">
    <a href="<?php echo $banner[$url][1]; ?>">
        <img src="/custom/banner/<?php echo $banner[$url][0]; ?>"/>
    </a>
</div>
<?php else: ?>
<div style="clear:both"></div>
<?php endif; ?>