Movie theaters where the audience does more than only watch together? How about they play together.
Given that these technologies are several years old, I am admittedly a bit late to the party. This does not diminish HOW FREAKING COOL THIS STUFF IS.
The basic interactions models are these:
The original work on these applications is detailed in the paper Techniques for Interactive Audience Participation. (Incidentally, one of the authors of this paper is Randy Pausch of The Last Lecture fame.) That paper as well as video and more detailed explanations and examples of use of these technologies can be found on the Audience Interaction page. Most recently these same techniques have been used for interactive advertisements preceding films in movie theaters.
It’s exciting to think of what could be implemented with this sort of audience interaction technology. Examples: creating choose-your-own-adventure-style films where the audience votes an outcome or directly involving the audience in certain action sequences. Using indirect means of measuring an audience’s input (like what’s been detailed above with perhaps the addition of auditory input) would prevent the cost and complexity of per-seat input technologies. Given the transition to fully digital film distribution and projection, the necessary computing hardware will soon be present in all theaters to render the actual result of audience interaction on-screen.