Volvo Repair: White smoke, white smoke, water vapor

Question
I have white smoke coming from the tailpipe of my S40. It is plentiful at idle and does not get any better as I drive. Runs and sounds fine other then that. What could it be? What could it cost to fix?

Answer
Tom,
Is it any different than other cars you see on the road? It could be water vapor that is visible only under some weather conditions. Water vapor will disappear as it gets further away from the tailpipe. Get back to me if you think your car has smoke, as opposed to water vapor.