As a follow up to my previous post I'm going to post some live examples of model layer with Zend framework based on Domain Driven Design concepts. I've spent the past few days studying up on domain driven design as well as a lot of Martin Fowler's work in relation to domain modeling and I think I have at least some code to start with that could get some conversations rolling.
Because of the lack of a standardized model layer in the Zend Framework, multiple methods for creating and using them are possible. Jim has created some examples with the Domain pattern to make a basic User class. His example shows how to create a User instance and run several methods on it (like getNickname, setNickname) and how you could pass it into an example web service as a complete object.