We are only at our fifth regular meetup locally here in Stockholm and while there have been both meetups in other parts of Sweden, a first meetup in Norway and an upcoming one in Denmark we weren’t really expecting it to spread quite as quickly as it has. Earlier today the first meetup outside of Europe was concluded in Winchester VA, USA.
It was arranged by @Mike1MB (you can find his blog here). Here, here and here are a few pictures taken at the event.
We hope that this, as it has been the case for us at TweetMeetup Stockholm, is just the first of many meetups to come and that it can act as inspiration to others out there to plan a meetup. It is easy and there are no set rules on how it should be done. The most important thing is to have fun and to meet people, and we have had a tremendous amount of positive response from all the meetups thus far. And the trend is that they are growing, both in size and in numbers. Meeting online is a good way to initiate a contact, meeting offline is an even better one to strengthen it.
The growing number of meetups and the added international spread has highlighted some areas of the site in need of improvement for better handling of international meetups and also increased the need for a way to document the meetups after the fact. Rest assured that both of these areas are being worked on and are expected to have been resolved within the coming week or so.
Until then I wish you all good luck on your next meetups! 
Meetup feed
We had a great time! Turnout was not as large as we wished, but that will improve.
We already have a volunteer to host another and she has also volunteered a location. This time we’ll use more that Twitter as vehicles to promote and advertise.
I expect we’ll go with that in a few weeks. I’ll be coordinating with my volunteer about the date but it’ll probably be a Friday evening.
Mike
Don’t worry about a low attendance on the first meetup. We only had six persons or so on our first meetup and 20 plus on our latest. Having fun time is the best promotion you could hope for. Attendees that had a fun time will tell their friends/spouse who in turn tells their friends etc.
We have also discovered that once a month is a good interval (at least for us).