This WordPress plugin/widget will display top commenters of your blog in the form of gravatar images. The images can be stacked up or listed in a sidebar box, linked to the commenter’s website. You can also change its behavior to display the current post commenters in a single post, also in the form of gravatar images. If your blog is powered by self-hosted WordPress version 2.8 or above, you can use this widget and place it anywhere within the sidebar of your WordPress blog. This widget should encourage your blog readers to put comments into your posts.