People who go to Meetups want action. I find that an action project that takes place at the Meetup tends to keep participants motivated to come again the next month.
I solicited ideas for action items that could take place during a Meetup in an earlier DailyKos diary. I also solicited ideas through a few Yahoo groups.
For those of you who host or attend Meetups, I hope this is helpful-- I've gathered the various ideas I've received, and also brainstormed a bunch more on my own. So, here are quite a few ideas for action projects that could be done while at a Meetup: