About IRL: MeFi Events
MetaFilter IRL (aka In Real Life) launched in June of 2010 and primarily concerns organization of meetups around the globe, but is also for listing other events a member might want other members to check out, attend, and congregate at. There are categories for not only meetups, but also performances (concerts, book readings, etc), presentations (lectures, speeches), and exhibitions (art openings, film screenings). The archives list past events and every event city has its own page showing upcoming and previous events as well. We also have a robust alert system that can email you automatically when something happening nearby. The Frequently Asked Questions page lists more common questions with answers.
If you'd like to know more about the MetaFilter Universe, read the about page for MetaFilter.