oltdev

This plug-in is a reporting tools for site administrators in WordPress MU. It generates a histrogram graph of posts and comments population in the system. Google Data Visualization API tool is used here to generate the graph.

Post and Comment Growth

Generates a graph to display population growth for posts and comments.

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.

Post and Comment Growth vs Category Text