Mozilla Labs' Contacts add-on for Thunderbird is a social networking superstar
Like the project they launched earlier this year for Firefox, Contacts for Thunderbird is all about connecting with your friends and acquaintances beyond your inbox and address book. Contacts can tap in to a number of sources, like Twitter, Facebook, Yahoo!, Gmail, and LinkedIn. It's extensible, of course, so you'll be able to add support for other sites (Orkut? Windows Live?).
Once you've logged in to a service the fun begins. Click on a Twitter user -- Soluto's Roee Adler, for example -- and interaction options are presented under Services:. I can send Roee a DM or view his updates right in the Contacts tab. Click a Facebook friend and you can view their updates, photos, and photos in which they've been tagged. Unfortunately, no Facebook messaging options are available yet.
Just like other Mozilla Labs projects, you're getting an early look at what could very well be a core feature in upcoming versions of Thunderbird. While it's lacking some features now, rest assured they're on the way -- Contacts will eventually provide a powerful, centralized dashboard for both email and social networking conversation.