I have user’s button presses on their cell phones being delivered via Twilio (thank you to the pirate pader who recommended it) to a Java application on my computer, using the HttpServer class in Java 6. You call my number, and then press buttons, and the numbers you press show up on my screen after about a half-second delay. I can also get your phone number (useful to differentiate users) and the home city/state/zip of your phone. And I can record your voice and play audio files to you, as well. So the basic technical challenge is solved. I still am not decided on my project, though. I’ve got several ideas for games that could be played on a large screen with many players. From the big-screen-lots-of-users interactions I’ve seen in the past, the challenge is to give each user enough control over the system to become invested in it. One should not feel one is fighting the other users in order to experience the game. I’m also thinking about what sort of things it would be cool to control anonymously with your phone. Like maybe a giant projection where each person gets control of a few pixels, and together people could build images. Or a radio station. Or a robot. The challenging with button-based interaction is that there’s no fine control there are only 12 binary switches, and you can only push one at a time, and there’s a half second delay before the system reacts to your choice. Perhaps a voice-based interaction would be better, although I don’t have real-time voice with Twilio. I can only record you and then download the recording asynchronously.