Charles Fulton

This plugin suppresses features of the Multisite site creation process:
<ul>
<li>It suppresses the welcome email sent to new site administrators on site creation</li>
<li>It cancels the site creation process if the given email does not exist, instead of creating a local user</li>
</ul>
It also flushes rewrite rules on site creation to address https://core.trac.wordpress.org/ticket/20171.
<h3>Privacy</h3>
This plugin neither collects nor stores any personal, private, or identifying information about any user.

Site Creation Utilities

This plugin improves the Multisite site creation process by eliminating undesired features.

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.

Site Creation Utilities vs Category Text