David Maister, whose work on professional services firms is legendary, has blogged about a study he did some years ago about waiting – specifically, what makes waiting more palatable. Among his observations are that people are happier with waiting when they know how long the delay are likely to be, and when they are informed as to the reason for the wait.
I can totally relate to that – some months ago, a doctor made us wait over 3 hours in a snowstorm with absolutely no information at all. We could at least have gone for a cup of coffee if we knew how long it was to be! It wasn't the ultimate factor in deciding not to return to that practice, but it sure didn't help.