Send digests with forum's active topics.

Allows an administrator to quickly and easily send a digest via Constant Contact service

The only all-in-one mailing list builder and email digest delivery plugin.

Allows visitors to register for receiving a weekly digest of the newly added posts.

WordIdentica is a plugin that creates a complete integration between your WordPress blog and your Identi.ca account.

WordPlurk is a plugin that creates a complete integration between your WordPress blog and your Plurk account.

SPNbabble Social plugin connects your blog to spnbabble.sitepronews.com and then connects to several other microblog sites including Twitter, Friendfeed, Plurk, Tumblr & Facebook.

This plugin collects the comments you posted on other people's websites and lets you display them on your own blog.