I learned a new way to test objects the other day.
We had a consultant over to talk about a TDD course he will be holding for RemoteX internally. During the discussion the suggestion to test an object by mocking the object itself came up.
What you do is, you use Rhino mocks (or similar) to create a partial mock of the object under test. What you override is the methods that will result in external communication.
This requires you to put all communication code in a single method, which you then override using the partial mock. The test then becomes, is the method for external communication called.
This reduces the amount of mocking code needed for more coupled objects, and also reduces the “IoC container for testability” need. Allowing the IoC focus to be focused on interchangeable parts.