Steph Locke has a presentation on Anchor Modeling as 6th Normal Form:
Anchor Modelling moves you beyond third normal form and into sixth normal form. What does this mean? Essentially it means that an attribute is stored independently against the key, not in a big table with other attributes. This means you can easily store metadata about that attribute and do full change tracking with ease. The historical problem with this methodology is that it makes writing queries a real pain. Anchor Modelling overcomes this by providing views that combine all the attribute data together.
Anchor Modeling is a rather different approach, so if it sounds interesting, check out the tutorial.