Other than that, I am trying to be simpler, more private, and add features that lead to events actually happening. I made a few departures from the meetup.com feature set already. First and foremost, I made a group scheduling feature where members help select the best date for an event. (I believe meetup doesn't have this, but I could be wrong.) Organizers can also email specific members, like those who haven't yet RSVPd or provided feedback.
Second, I allow the username space to be group specific. This is a subtle, but important, difference imo. This allows for each group to have a "Mike," "Joe," etc., i.e. it lets people use the handles on-line that they are using off-line within their local groups. It works seamlessly to the user as they just provide a handle for each group they join, which will probably be the same name each time.
Third, everything is private by default: email addresses, profiles, etc. Members can send private member and group messages that get emailed but don't display addresses. Replies forward through us seamlessly. On meetup I was put off with the fact that my name and profile information was almost immediately indexed by Google and available to the public. Maybe no one else cares about this, but I do.
