Sign-up list

Below is an example of how I could use a sign-up list/'show of hands' - an actual message what I posted to our groupsite in lieu of this. I'd use this feature several times simultaneously in each groupsite. Such a feature would compel members to invite others to join in order to reach the sign-up list benchmarks for action. For a company that bases it's entire business model on a sign-up list, see www.eventful.com, which books bands once a certain number of people in one city sign up to commit seeing a band.

The simplest function would be to have an event with no date - RSVPs are essentially sign-up lists, but I'd like to have sign-up lists for tasks, projects, goals, committees, groups (ie anything I want) rather than just for events.

"Allan, the owner of Chief Ike's, would welcome the possibility of opening during the day with tables and chairs, outlets, wi-fi and a dayworker menu if there was an interested group of dayworkers committed to being there - at least 20 at any given time. There's no sign-up list in this system, so please simply reply to this thread, and once it hits 20, we'll set up a meeting with Al to talk about this."