Exit interview hint (not that I'm having one soon, at least that I know about):

Many people will tell you to be completely positive as you leave. This, overall, is a very very good piece of advice. Focus on the good things that happened there. Remember, pointing out all that's wrong now will only leave a bad taste in the mouth of your soon-to-be-ex-employeer. You're no longer around to provide context for these issues, to back up what you think. Instead, you'll have given criticism without construction, so to speak, which makes for nothing but a complaint. They were paying you to point out what was wrong before. Now, you're going somewhere else, and it's time to play the ritual.

Now all that in mind, I think the exit interview allows you a great opportunity, if you do really care about where you work[-ed], to put *one* piece of constructive criticism on the table. It must be well-thought out, you must be as concise as possible, and you must not, under any circumstances, start debating particulars. You'll find many managers will be somewhat surprised that you'd mention a problem and quick to characterize it as a parting shot. Instead of getting bogged down in particulars (though you should have quite a few examples in your head) where your ex-manager can nitpick and feel the problem doesn't exist, simply use your bowing off the stage as an opportunity to broach the subject, blazing the most difficult part of the trail -- the trailhead -- for those who might voice the same concern in the future. Hopefully that future response won't be, "You''re missing the mark," but instead will be, "Ah yes, [ex-employee 14423] mentioned that as well. And here's someone else who believes the same thing. Perhaps I should deal with it."

You'll become somewhat symbollic with this sort of parting gesture, and that's a good thing. Keep it positive, short, and constructive, without example (as anti-intuitive as that seems), and keep the rest of the exit interview horribly upbeat.