I’ve been using Twitter Tools for some time now and found it quite useful, however, a much simpler plugin is “Facebook/Twitter Status Updater.” It updates both twitter and Facebook, and it allows you to specify a different headline for the update, instead of just using the post title. Twitter tools also requires something to be appended to the beginning like “Blog Update:” and this plugin doesn’t.
Twitter Tools has many more advanced features for Twitter, but lacks the Facebook update. If all you want to do is update your blog, Twitter, and Facebook from one place, this is the plugin for.
The only drawback I can see is that if you’re logged into Facebook when you publish a post, you will be automatically logged out.