Implements Project Honey Pot's http:BL service for Drupal. http:BL can prevent email address harvesters and comment spammers from visiting your site by using a centralized DNS blacklist. It requires a free Project Honey Pot membership. This module provides efficient blacklist lookups and blocks malicious visitors effectively.
httpBL has been adopted for use to enhance protection on Drupal.org.
This module provides a 'Stumble' link in each node page that allows users to visit another random node (think StumbleUpon for your own site). It was inspired by Matt Mullenweg'sRandom Redirect plugin for WordPress.
The Mass Contact module allows anyone with the proper permission to send a single email message to multiple users of a site, even to all the authenticated users. There are currently two methods for select users: either with user roles or taxonomy.