There's an oversight: You have added the non-regular April meet-ups as "upcoming".
This was actually posted on the 27th of April. I believe the date at the top indicates the last time the post was changed (when I moved it to discussion).
There are upcoming irregularly scheduled Less Wrong meetups in:
The following meetups take place in cities with regularly scheduled meetups, but involve a change in time or location, special meeting content, or simply a helpful reminder about the meetup:
Locations with regularly scheduled meetups: Austin, Berkeley, Cambridge, MA, Cambridge UK, Chicago, London, Madison WI, Melbourne, Mountain View, New York, Ohio, Ottawa, Oxford, Portland, Salt Lake City, Seattle, Toronto, Waterloo, and West Los Angeles.
If you'd like to talk with other LW-ers face to face, and there is no meetup in your area, consider starting your own meetup; it's easy (more resources here). Check one out, stretch your rationality skills, and have fun!
In addition to the handy sidebar of upcoming meetups, a meetup overview will continue to be posted on the front page every Friday. These will be an attempt to collect information on all the meetups happening in the next weeks. The best way to get your meetup featured is still to use the Add New Meetup feature, but you'll now also have the benefit of having your meetup mentioned in a weekly overview. These overview posts will be moved to the discussion section when the new post goes up.
Please note that for your meetup to appear in the weekly meetups feature, you need to post your meetup before the Friday before your meetup!
If you check Less Wrong irregularly, consider subscribing to one or more city-specific mailing list in order to be notified when an irregular meetup is happening: Atlanta, Berlin, Helsinki, London, Marin CA, Pittsburgh, Southern California (Los Angeles/Orange County area), St. Louis, Vancouver, Washington, DC.
If your meetup has a mailing list that you'd like mentioned here, or has become regular and isn't listed as such, let me know!
Want to help out the common good? If one of the meetups listed as regular has become inactive, let me know so we can present more accurate information to newcomers.
Also: Nickolai Leschov is collecting information on all LW meetups, and is working with Luke Muehlhauser to provide helpful materials and maybe even some coaching. If someone from your meetup isn't currently in touch with him, shoot him an email for great justice. More information here.