I know there is a way of getting the WP category list:

<?php wp_list_pages ($arglist); ?>

but does anyone know of a plugin or method of getting a linked list that is X width on multiple lines?

I want to put my category list in the header of a blog I run as well as on the side because the category list on the side is pretty low and I think I can get better click-thru if they are at the top.

My suggestion would be to look into a plugin called Ultimate Tag Warrior. It can automatically create tags from your categories, and has a ton of different display options (ordered lists, clouds, etc). But you'll want to do one of the following:

1. set the directory structure (in the options) of UTW to make the tag URLs the same as your category page urls. That way there won't be duplicate pages.

2. if you can't figure that out, then you'll have to disallow either the category pages or the tag pages in your robots.txt to avoid duplicate content. Probably best to disallow whichever isn't already indexed and ranking. ONLY if you can't get #1 to work.