New blog engine idea

This is my first "post" here and i wish not a last. Also please don't blame me for my english. In 2009 i start to learn Rails and this is not surprise -> i start to write my blog engine. it looks like a simple blog with basic functionality (posts/custom-fields/tags/categories/users/roles) And some idea come to my mind. Lets imagine what you have friend with cross interests, like ruby or any others. And you want to keep your readers about this man and his posts about ruby. So, you send invite to his blog and get back answer. If your request will be accepted -> your readers will see new posts from your friend. You can configure : full posts or only first part or only link like twitter. This will create a relationships between many blogs. It's like track-back in wp, but track-back is only tech side of this. Because this is Friendly blogging. So, what you think?