Almost there with this...just need to show the jquery slider on the home page.
Instead of using 'catalog' is there another way of hiding the top code on the category pages but showing it on the home?
{if ($main neq 'product' and $main neq 'catalog' and $main neq 'catalog' and $main neq 'cart' or $cart_empty) and $main neq 'checkout'}
<div id="banner">
Jquery banner thing
</div><!-- / banner -->
{/if}
{if $current_category.category neq ""}
<div id="banner">
<img src="{if $current_category.icon_url}{$current_category.icon _url}
{else}{$xcart_web_dir}/image.php?id={$cat}&type=C{/if}" alt="Alt here" />
</div><!-- / banner -->
{/if}