I organize a number of technical meetups, such as HelsinkiJS which is the biggest developer meetup in Finland, and have found Meetup.com lacking. To scratch our own itch, we built Meetabit which includes some additional features such as the ability to accept talk proposals and sponsorship offers, have speaker profiles, archive of talks and related materials, export data etc.

It does what we need and we haven't been actively developing or promoting it recently, but it has still grown organically to around 10K users and multiple meetups organized each month. We are likely to put more resources into it given the recent changes at Meetup.com. Worth adding that the service is free both to organizers and attendees; our long term plan is to have the same business model as Stack Overflow by promoting relevant jobs to members.

I'll draft a blog post explaining things in more detail, but in the meantime feel free to ask questions in the comments below. Also, if you'd like to take the service for a spin and your city isn't listed, shoot me an email at [email protected] and I'll add it.

PS. Nicolas has added us to the linked post since I made this comment, many thanks for super quick responses!