I just run into a nice blog post by Neil Martin ("Prototyping : New wine, old skins") where he shows how to abstract data access with db4o as the underlying persistence engine (Nail is a big fan of repositories and finders, updaters and basically any technique to abstract data access and easily Mock the data layer).

Source code is included (C#) and a brief explanation on how to inject the repository against the IoC framework Unity.

We look forward for Neil's follow up blog post!