Beau Lebens

Allows you to use a shortcode in your Posts and Pages to embed a Gravatar quickly and easily just using an email address.
<h3>Options</h3>
In addition to email=””, you can also include the following attributes within the shortcode for extra formatting etc:
See http://dentedreality.com.au/projects/wp-plugin-gravatar-shortcode/ for more examples.
<ul>
<li>email: the email address to display the Gravatar for</li>
<li>size: a number (e.g. 60) representing the pixel size of the Gravatar to display (they are square)</li>
<li>rating: a letter restricting the maxiumum rating of Gravatar to display (g, pg, r, x)</li>
<li>default: the default image to use if there isn’t one associated with this email address (otherwise it will use the Gravatar.com default)</li>
<li>alt: the “alt” attribute to apply to the img tag produced</li>
<li>title: title attribute for the img tag</li>
<li>align: align attribute for the img, should be left, right, absmiddle, baseline etc</li>
<li>style: custom style attribute (e.g. ‘margin: 5px; border: solid 1px #000;’)</li>
<li>class: add a class to the img tag</li>
<li>id: add an id to the img tag for specific styling/DOM manipulation.</li>
<li>border: adjust the border attribute for the img</li>
</ul>

Gravatar Shortcode

Allows you to use a shortcode in your Posts and Pages to embed a Gravatar quickly and easily just using an email address.

Dougal Campbell

This plugin allows you to automatically add Gravatars for commenters to your 
theme, if your theme does not already support them.
According to the Gravatar.com website, Gravatars are Globally Recognized 
Avatars, or an “avatar image that follows you from weblog to weblog 
appearing beside your name when you comment on gravatar enabled sites.” 
You register with the Gravatar server, and upload an image which you will 
use as your avatar. The gravatar image is keyed to your email address, so 
that it is unique to you.
This plugin will display gravatars for the people who comment on your posts. 
You do not need to modify any of your template files — just activate the 
plugin, and it will add gravatars to your comments template automatically.
<h3>Credits</h3>
Based on a code snippet from Matt Mullenweg: 
 http://photomatt.net/2007/10/20/gravatar-enabled/ 
 http://pastebin.ca/743979
Props to David Potter for pointing out that Gravatar normalizes email 
addresses to lowercase before hashing with MD5: 
 http://dpotter.net/Technical/index.php/2007/10/22/integrating-gravatar-support/

Easy Gravatars

nice

Add Gravatars to your comments without modifying any template files. Just activate, and you're done!

Gravatar Shortcode vs Easy Gravatars