Funny, I was at my local Cobb Theater yesterday to see Dark Shadows. They have a new ad campaign now about "What does your phone do when it sleeps or Does your Phone Dream when it sleeps?" It gives a number to text to and then they tell you to turn off your phone and when you turn it back on, AFTER THE MOVIE, you'll get the answer.
I didn't try it. Just thought it was a nice idea to get the ringers off in the theater.