WordPress.org

1. Upload the files to the /wp-content/plugins/moo-gravatar-box/ directory
2. Activate the plugin through the 'Plugins' menu in WordPress
3. Add this to your comments form somewhere: if (function_exists('moo_gravbox')) moo_gravbox();
4. Add styling for it into your style.css. The moo_gravbox() code adds a div with id of "gravbox". The image has the "gravatar" class, and is wrapped inside another div with a class of "gravatar_frame". The no-gravatar link is inside a p with a class of "nogravatar".

Further and more easily configurable options will be available in a near future release.