Surely most, if not all of us, have fantasized at one point or another about quitting our jobs on the spot, getting up and just walking out, either silently slipping out an exit door never to be seen again or adding a little fanfare to the occasion and going out with a touch of bravado by telling your boss and coworkers what you really think of them. Yet, for most of us, these fantasies will remain exactly that. When it comes to employment, there's too much at stake, and when you burn bridges,…