Lorna Timbah

This plugin creates a widget to show the top commentators in your WP site. Always go back to the Widget settings after each version update to Save your settings. Demo can be found at http://demo.webgrrrl.net
The Top Commentators Widget plugin is adapted from Show Top Commentators plugin at Personal Financial Advice, this widget is easier to manage via the control form (no need to edit the PHP file); additional options are also available to make it more flexible. Read the FAQ section on how to customize the widget. Read the Changelog as well as http://webgrrrl.net/tags/tcw for the latest news on this widget.
This widget is extensively tested with the following settings: Google Chrome 13.0.782.215 m, PHP 5.2.13, Apache 2.2.15 (Win32), MySQL 5.0.51a, WordPress 3.2.1. Further testing and bug report on this widget is greatly welcomed and appreciated.

Top Commentators Widget

Adds a sidebar widget to show the top commentators in your WP site. Demo: http://demo.webgrrrl.net

Marcus (aka @msykes)

Pixelite

Marcus

This is a very simple and lightweight plugin that anonymizes default avatars and prevents the user’s gravatar being automatically obtained from gravatar.com based on their registered email. This would be useful for sites where users require an extra layer of privacy, or if you just want to prevent potentially silly or embarrasing avatar accidents.
If you’re using Identicons or any other generated default avatar, the user should keep a consistent avatar unless they change their registered email.
You can also disable Gravatar completely and choose a default image to display.
This plugin is also compatible with other avatar customization plugins such as <a href="https://wordpress.org/plugins/avatar-manager/" rel="ugc">Avatar Manager</a>, <a href="https://wordpress.org/plugins/buddypress/" rel="ugc">BuddyPress</a> or <a href="https://wordpress.org/plugins/add-new-default-avatar/" rel="ugc">Add New Default Avatar</a>, since this plugin specifically prevents the gravatar of a specific user email being used and reverts to the default or user-defined avatar.
Important 3.0 Update – BuddyPress users should visit the Settings > Discussion page on your dashboard and choose one of the Disable Gravatar options to restore previous behavior.
If you have any issues or suggestions, please visit our <a href="https://wordpress.org/support/plugin/disable-user-gravatar" rel="ugc">support forums</a>.
If you find this plugin useful and would like to say thanks, please leave us a <a href="https://wordpress.org/support/view/plugin-reviews/disable-user-gravatar?filter=5" rel="ugc">5 star review</a>!

Disable User Gravatar

The plugin is a must-have for each WordPress installation. One can't process the email of the user (personal information) to create a hash and sent it to a remote server without consent of the user.

Must-have

Stops WordPress from grabbing a user avatar using their registrated email from gravatar.com.

Top Commentators Widget vs Disable User Gravatar