Hi,
as a start, you can change the look of a category menu PAGE by using your own CSS.
eg
I have a FAQS menu which reads:
{* $Id: faqs_menu.tpl,v 1.13 2004/05/28 12:21:09 max Exp $ *}
{section name=pg loop=$pages_menu}
{assign var="tmp" value = $pages_menu[pg].pageid}
{if $tmp > 2 }
<link rel="stylesheet" href="{$SkinDir}/skin1_myxcart.css">
{$SkinDir}
{$pages_menu[pg].title}
{/if}
{/section}
This changes the layout of all the items on the FAWS menu. You could easily filter on a per page basis something similar.
Hope this helps a bit.
VixnFox