I'm working as a postdoc on a project that studies cooperative communication by having people play an online two-player computer game involving bombs and hostages and killing badguys. It's not a particularly high-tech game, but most people who have played have had fun. I've discovered the best way to do this is to get a group of interested people to meet online at a designated time and play for an hour or two - this way, no one has to wait ages for a partner (we lose a lot of players that way), and people tend to talk to each other more. If you play through Amazon Turk, you even get paid at the incredibly lucrative rate of a dollar a game, with the possibility of earning a (gasp!) fifty-cent bonus! My friends are pretty well mined out by this point (although a few of them like the game so much they apparently want to play again), so now I'm trying to find new people who might be interested in rescuing some hostages For Science.
You can find out more about the game, and the project it's part of, here:http://www.seas.upenn.edu/~muri/pragbot2.html
If you're interested in playing, email me (Irim) and I'll give you her email address so you can get in touch.