Look in the Alloy MVC sample site. You will find a good solution in the partial view "SubNavigation". It uses an extension method (HTML-helper) that takes a delegate. The delegate are created in the view and passed to the helper method.
This is also a interesting approach :)
I was hoping for other ideas than the one in the Alloy sample site. That one feels a bit overengineered.
Can't find any good resources on how people have implemented page navigation (submenus) with several levels.
Would be very interesting to see how people have solved it. I'm struggling a bit in doing it the EPiServer way and would appreciate examples greatly!