You don't need to put together a team, just show up. You don't need to even be good, just come have fun. You don't need to invent your own war cry to strike fear into your opponent's soul, but it helps.
These games are not exclusive to Meetup.com... anybody can join (but they are 21+). We usually play 'til about 8:30 or 9:00.
Pictures and any last minute schedule conflicts will always be on Facebook so you should join up there also.