isikom

Category Text add a widget that allow to add arbitrary text or HTML code, different for each category of your blog. 
It’s very usefull for SEO, because you can make different text for different category, so also different banner etc. 
Now you can select also the home page position.
The plugin born from idea of <a href="http://www.rossozingone.it" title="web agency" rel="nofollow ugc">Vanny Rosso</a> for his blog <a href="http://www.fantagiochi.it" title="on line games" rel="nofollow ugc">Fantagiochi</a>

Category Text

category text allows you easily to add a widget for a Category Text-Box.

Brad Williams

This plugin lets you create category mappings allowing for one top-level blog to act as a portal for your global community of WPMU blogs. Category postings are aggregated based on the mappings and displayed on the top-level blog.
Features:
<pre><code>* Map multiple top-level categories
* Built-in sidebar widget to display all categories
* WordPress MU 2.7 approved!
</code></pre>
<h3>Plugin Support</h3>
<a href="http://webdevstudios.com/support/wordpress-plugins/" title="WordPress Plugins and Support" rel="nofollow ugc">WordPress MU Category Mapping Plugin</a>

WordPress MU Category Mapping Plugin

Plugin links categories network wide to provide one top-level blog to act as a portal for your global community of blogs

Category Text vs WordPress MU Category Mapping Plugin