Unless it is really bad, I would suggest leaving it alone. If the engine sits for a while a little smoke will come out when the engine heats up but will stop soon. You can't prevent it... it will leak a drop or two... it is going to happen if the engine sits. Anyone that got theirs fixed and it stopped leaking, more power to you. Chances are it will come back again. I personally would not let anyone touch the valve cover gaskets unless it was really bad and you can smell it inside the car.

My car sits for a few weeks at a time. I noticed just a little bit of smoke as you describe. I worried at first until I started to realize it was no big deal. You can't get the seal 100% tight and a few drops won't hurt anything. You could do more damage by having some kid at the dealership take the cover off. If they drop something in there or don't know what they are doing it could be a problem. If they put it on there it may stop leaking a few weeks and then start back up again worse than it was. To me it is not worth the risk. Some people here would say I was crazy and wrong.... but to me it is not worth the risk unless the leak was really bad or it was spilling on the floor of the garage.

Don't be so fast to run to the doctor with everything.... chances are you will have a different problem when you come home! I had bad experiences at the dealership so the less they touch my car, the better off my car is!