For a while I have been using TwitterFeed to automatically announce new blog posts on Twitter, but I stopped using their services and am considering to stop following others who are announcing every single post on Twitter.
I love Twitter to follow what people are doing, and what they are thinking, but in most cases I am not interested in every blog post. And if I am, I simply add their blog to my feedreader. It is OK with me if you point out some of your excellent blog post in Twitter, but, please don't make it automatic. In my opinion, TwitterFeed only adds noise to Twitter.
By the way, if you are also on Twitter, my ID is JeroenSangers. I am also on FriendFeed, with he same ID.