You know what would be great - this combined with the Mod someone mentioned that lets you time-release a thread. (Can't remember the official wording.) So you could set up a thread to be posted on X day at X time and the first person to reply gets a trophy.
And then for the ultimate game thread Mod, if it would also self-close at a pre-determined time you could have a game of Thread Hot Potato where the last person in a group to post before it closes gets is out of the game.