In the New York Times today, there is an article with 15 rules for theater etiquette. Thank you, thank you, thank you to the author! You can find the article by clicking on this post's title.
In this day and age, when common courtesy seems to be a rarity and our once-known and -observed respectful actions seem to have all but disappeared, this list would return theaters (including movie theaters) to environments where you could go for good entertainment feeling like the play, concert or movie was just playing to you (since you wouldn't be distracted by your audience neighbor).
Let's get back to some sanity and self-control!