I've had many posts on unit tests and here goes still another one. I can't count how many times I've heard that unit tests are a waste of time. Managers, pressed for a release, are "ok" if you check in without unit tests. Unit tests, when there's pressure, becomes "optional" and, compared to all features you could be implementing instead, go to the bottom of your priorities list. Yes, these are the chats I have - and no matter how much one tries, it's almost impossible convince otherwise.
Dr. Dobbs published a small text on unit tests called "Unit Testing: Is there really any debate any longer?", which is great and reflects precisely my experience. Still another shot at convincing the opposers :-)