I have just added the Linkback extension that provides Pingback and Trackback clients and servers for blogging applications.
The client side is a behavior that is attached to and called from the controller that displays posts.
The servers are implemented in a controller.
To suit as many applications as possible single and multiple blog schemas are supported, blog (in muti-blog applications), post and feedback models are defined in the configuration, as is the attribute mapping of the feedback model onto the server.
This changes the clients to a filter that is applied to the controller/action that displays individual posts. Using a filter greatly simplifies adding the auto-discover code to the post (thanks to Qiang for pointing this out).
It is strongly recommended that anyone using V1 changes to V2 of this extension.
Nice Extension thou I am still having trouble getting it functional, Your documentation is excellent except for more detail in the examples. maybe you could show how to get this working in the blog example provided in the default Yii installation.