Unit Testing with Mock Objects (and Spring)

I was looking into some information on how to do unit testing using mock objects. Since I'm using Spring, I'm also considering this into the equation.

So far, I have found some nice articles, like this one linked from TheServerSide, which talks about unit testing and mock objects in general, and provide some examples.

I have also found several mock object libraries:

• EasyMock
• DynaMock
• jMock (It's actually DynaMock redone)

I'm wondering what people have done in this area. It seems that using mock objects is an ideal match for unit testing, and something that should be more thoroughly integrated.