Episodes that take place all in one location, or “bottle” episodes, are frequently used in television to help save a few dollars in the production budget. This is especially true when shows like Lost and 24 spend most of their budget for the season on episodes full of explosions and other costly effects and then need to make up those costs in other episodes. However, movies that all take place in one location are harder to come by. Movies generally have bigger budgets and can afford to shoot in a number of locations but those that do choose to lock all their characters into a room for the duration of the movie generally benefit for it. Now, of course I'm not saying this is a law, but it makes sense, especially for movies on a tight budget. Without having to spend a lot of money shooting in a lot of locations or on big budget effects, movie that take place all in one room focus their efforts on what really matters: the plot and it's characters. Movies like 12 Angry Men and My Dinner with Andre have been lauded for their deep study of the characters involved, and I believe eliminating the distraction of things that can't happen in one location play a part in that.