mu (Microblog Updater) is a plugin that farms out links to your posts to your microblogs.
mu works using PHP's cURL libraries and supplied user data to send out updates to whatever social networks you've signed up for. When you publish a post, mu steps in and grabs your post's permalink and whatever short description you've supplied and sends it off. The only setup required by a user is the initial choices for default services, when to send updates, and credentials for the user's accounts.