I agree with Paul. Meetup has been around for a long time, and have improved the product over this time. We at Treetle (http://www.treetle.com) launched our product that is a similar service to meetup, but completely free to use (yes, completely free!) a couple of weeks ago globally. Lot's of great features and we add more every day. The UI is simpler too (in our opinion). Give it a try and let us know what you think. Mobile app on the way as well.