I thought I was letting people know that they were going on - kept changing the title of the thread, hassled people... I didn't always find everyone who was on though. Yesterday, I think we waited 2-3 hours to start a round because we didn't have enough people for that long.

edit: I think that if we do this sort of thing again, we'll have a sign up sheet for people who are interested in playing so we can send out PMs to alert people.