changing a post to category

HI,

I am using an Organic Themes template, it’s great other than it has a Portfolio template which links through to single posts, I would like the portfolio template to link the category template with items from that category listed.

So my client has several products displayed within the portfolio page, when one of these products is clicked on it needs to display several types of that product just as the category template does.

Can anyone please advise me as to how I should change the code to do this?
Seems like it should just be a change of this link;
<h4><a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></h4
I guess that’s too simple however…. as it needs to fetch the category that post is in, display other categories in there on a category page….?

Any help VERY much appreciated.
x