Managers: Here's a paradigm shift you should use when you are evaluating employees for upcoming promotions. Be suspicious of "brown-nosers" and "yes-men".
It is most likely that the employees who are sucking up to you are doing so because they are the least competent at their jobs and know it. Your most productive employees do not have time to suck up because they are busy doing actual work. To really improve productivity and morale, reward those who are productive, rather than those who spend all their time telling you how productive they are.
As an exercise, fire the next person who comes in and sits down in your office just to ask how your weekend was. That person is a slacker. You should see a sharp boost in productivity soon after. (Of course, that sort of termination may not be allowed in a union shop. In such circumstances, you may ignore this advice, because your company will likely be bankrupt in a couple of years anyway.)