At the moment I'm working on a method of forming a party in Driftwurld.
The idea is that you work as a team by each of you dealing with a random scenario that you face. You then have a number of options you can choose from as a response, one of which is the right response (which you discover either by experimentation (or paying!) then need to remember it (it's a small memory game).
The response you give is actually sent to another player as a signal. When they log in, they see the signal you gave as to what action to take and they have a number of options shown to them. Their part in the team play is to follow the direction you gave them and hit that option.
If they do and you gave the right signal to begin with, you get tactical strength points, which make the battle a hell of alot easier (read: less horrifically expensive) to fight.
And likewise, they will be getting a random scenario and then sending a signal to you to respond to as they direct as well. It's like everyones giving each other commands - so everyones the leader for a moment, telling others what to do, then it switches around equally and you follow their directions. Do it all right and you grow strong as a team!