I use Rhino Mocks pretty much exclusively for mocking and testing. I find that there really isn't anything that I've wanted to do that I haven't been able to figure out how to accomplish with Rhino Mocks. What is everyone else using? I'd like to know so I can take a look. Anyway, as you know, with Expect.Call we can return property values, return values from functions, throw an error, etc. Sometimes just returning a static value isn't going to work, or it's just easier to give it some simple code...