Regarding the Developing Women meetup (sorry, I couldn’t resist), I think a Facebook page or Ning is an excellent starting point and wouldn’t be too hard to put together. You’re sufficiently well connected at this point to get the word out, all it would take is a few well-placed retweets and you’d probably get a core of members interested. Take Nick up on his offer, get a range of possible dates/times, and submit those in a poll to the group to see when you can get the most people there. The first meeting can consist of introductions and a discussion of what direction everyone wants to focus on and how often they want to meet. For instance, it might be interesting for members to take turns giving quick lessons on their areas of expertise/interest (even if it’s “only” learning resources they’ve found), or maybe there’s a group project like a charity or open source project everyone would like to get together to work on. Also, it’s vital that someone bring vegan refreshments.

It’s equally beneficial to make it a social hour, but I’ve found the key to survivability with these things is to make everyone feel involved by contributing to the group. That also benefits you as the facilitator so you’re not put in a position of entertaining a bunch of people at every meeting. I’m sure you’ll agree that would be a good thing.