I just finished a sample implementation of how to use db4o (an open-source native object database), and WinForms databinding in the sweetest little app. My database logic is only a few lines of code, and almost everything was settable in design-time with no Visual Studio extensions, O/R Mappers, automated code-writers, etc.
Download the application at http://www.everylittlething.net/PartsAssembly
Requires nothing but Visual Studio 2005 and db4o.