In a recent project I've been working on, we have used the 'Domain Model' to describe and design our application. Doing so we decouple persistency logic from the objects that are being passed around and modified throughout our application: The Domain objects.

He talks about challenges associated with the development (issues separating out the business logic) and how they solved it in two ways - reflection and a pattern where the domain object uses itself. Code is also included to help illustrate the problem and these two methods of resolving it.