Social bookmarking allows users to submit, comment on, and “promote” websites. The Gregarious plugin supersedes the Digg This Reloaded Plugin and allows for seamless integration between your Wordpress Blog and social bookmarking sites such as Digg.com, Del.icio.us, Reddit and more. Requiring no editing of templates, and a simple point and click interface, Gregarious is the ultimate social bookmarking plugin for Wordpress. There is one downside of this plugin only, due to time constraints, the author is no longer guarantee support for this plugin.

Pricing: Free
Requirements: -
Source: http://lipidity.com/web/wordpress/wp-plugin-gregarious/