I had a query this morning about this. Say you're working in the new MVC framework and you write your own routing engine that has a syntax like this:
Route("some string pattern").IsHandledBy<MyController>();
Route("some other string pattern").IsHandledBy<AnotherController>();
Each Controller has its own set of dependencies that you'd prefer that StructureMap build out for you, but it might be inconvenient to have to register all these types with StructureMap. That's okay. As long as you know the concrete type you want, StructureMap can create the concrete class and "fill" it with all of the dependencies even if StructureMap isn't configured with that concrete type in advance. The syntax is:
MyController controller = ObjectFactory.FillDependencies<MyController>();
or
MyController controller = (MyController)ObjectFactory.FillDependencies(typeof(MyController));
I don't use this feature much, but it's handy in some spots