WordPress.org

This plugin auto-detects and shows in real-time the Gravatar image when users are filling the comment form, with a nice fading effect. It's fully customizable through the options page. It's a fork of the "Gravatar Box" plugin by Otto42, based on the MooTools javascript framework (instead of jQuery).

Please note that as of now the code has changed from gravbox() to moo_gravbox(), in order to fulfill a more than reasonable request from Otto.

Plugin Homepage

http://www.3dolab.net/en/mootools-gravatar-box