The Bakery has a new CakePHP tip posted today showing how to improve the unbindModel handling on the model side of things (versus in the controller as mentioned previously).

The problem with that solution is that it requires you to change the way you define your model relations. [...] Rather try to change your code to suit your needs, and let CakePHP do what it does best: act as a framework.

The technique approaches the associations differently - loaded and called when you make the call to expects() versus just automatically. They include the code to make it all work for an extension to the Model (AppModel), and extension to the AppModel (Title), and finally the TitlesController that shows the deliberate calls to expects to pull in the models.