Now you may have seen from the other WordPress news that Gravatars has become part of Automattic. You may be thinking how can I integrate the avatars into WordPress, while the Automattic team works on the application and rewrites it into the WordPress rails?
The simple solution is: a plugin. Its just as simple as any other plugin, place it in wp-content/plugins and then activate in the admin panel.
There are some options you can choose from like size and rating of the Gravatar also if your feeling brainy you can even edit the CSS code to your liking.
Download the Gravatars Plugin.