Commentia

Commentia is a small, quick and easy to use plugin that allows multiple classes to be assigned to comments based upon a users role or permission level (Administrator, Author, Editor, Contributor, Subscriber, Guest). Each role gains a different class, allowing full customization of a comment.

Download: Commentia v2.0 - Wordpress 2.1.x
Demo: Any and all comments on this site

Installation
  1. Download the latest version above
  2. Un-zip the folder onto your desktop or computer
  3. Upload the file commentia.php into your /wp-content/plugins/ directory
  4. Active the plugin through the "Plugins" menu in the Wordpress Admin
Implementation

1. Download the latest version from http://code.mileswjohnson.com/plugins/commentia/
2. Un-zip the folder onto your desktop or computer
3. Upload the folder /commentia/ into your /wp-content/plugins/ directory
4. Active the plugin through the "Plugins" menu in the Wordpress Admin
5. Open the comments file from the theme editor and find the <li> that displays each comment
6. Place the following code <?php echo mjx_commentia($oddcomment); ?> as so:

<li class="<?php echo mjx_commentia($oddcomment); ?>"> .... </li>

Note: $oddcomment would be the alternating class variable, or you can supply your own class.