I’ve been using the Twitter Notify plug-in via Live Writer to post new blog post notifications to Twitter, but there are problems with that approach. It doesn’t work when I post from the WordPress Dashboard, or when I (try) to post with the WordPress iPhone app. So I went looking for a better method, and came up with WP to Twitter.
You can configure WP to Twitter to do just about anything short of tying your shoes. You can configure it to work with several URL shorteners, including Bit.ly. You can configure it to Tweet new posts (good) or edits to posts (with my typo-correcting requirements, bad). You can customize the content and sequence of the Tweet, convert tags to Twitter hashtags and more.
Best of all, it will automatically push new posts to Twitter, regardless of where and how the post is created.
All in all, pretty nifty.