WP-Gravatar. This plugin lets you use Gravatar, MyBlogLog, OpenAvatar, Wavatar, Identicon, monsterID or Favico.ico files with your comments.
But thats not all, scroll down to see what else this plugin does for your site. The plugin has been tested on version 2.1, 2.2, 2.3.1, 2.3.2, 2.3.3 and 2.5. Should work on all versions from 2.1 and upwards. It will also detect the Prologue theme from Automattic. WP Greet Box WordPress Plugin « OMNINOGGIN. Today I would like to announce the release of ‘WP Greet Box’ WordPress Plugin, a plugin that can help you increase your blog exposure and build loyal readership. Description This plugin lets you show a different greeting message to your new visitors depending on their referrer url. For example, when a Digg user clicks through from Digg, they will see a message reminding them to digg your post if they like it. Another example, when a visitor clicks through from Twitter, they will see a message suggesting them to twit the post and follow you on Twitter.
You can also set a default greeting message for new visitors (not matching any referrer URLs) suggesting them to subscribe to your RSS feed. Subscribe to Comments. WP-OpenID.