Tell people in advance that there's a Less Wrong sign and that they don't need to worry too much about finding the right people is a great suggestion. I added it to the meetup guide (the "Making the announcement" section):
Wherever it is that you are meeting, you’ll want to bring a sign from which people can recognize the right group of people. Mention the fact that you’ll have a sign in the meetup notice, or offer some other easy visual cue for recognizing the group! This way, people don’t need to be nervous about whether they’ll find you. This is especially recommended if you’re meeting in some large location.
Meeting fellow LessWrongians in meat space is a great opportunity to participate in interesting discussions and to make new friends. But there aren't that many places in the world (hopefully, yet) where regularly active meetup groups exist. Here is a story of how I realised that setting up LW meetup groups is much easier than I thought; and an idea of an approach to help build more LW communities in real life.
When I co-organised the LW meetup group in Cambridge, there was already a group of friends irregularly discussing LW related topics. Strangely, it took us some time before we actually realised that we should announce a meetup on the LW website. Once we did that, our group exploded in numbers and we have had regular meetups almost every week.
Of course, Cambridge, UK is a place where we expected to be successful in forming a meetup group. It is small and the concentration of usual target audience of LW is extremely high. I thought we were lucky with the location that creating a regular meetup group proved to be so easy.
Then I had an idea of an experiment. I was travelling to Budapest last week for 3 days to visit my family and I thought that I would simply try to organise a meetup there. In the worst case, I would spend a couple of hours in a cafe reading a book. My guesstimate was that 3-4 of my friends (whom I reminded several times) and maybe 1-3 people I don't actually know would turn up.
I was surprised to find that 14 people attended the meetup, two of them travelling all the way from Bratislava to Budapest. We spent almost 4 hours in a fantastic discussion, a mailing list was created, and a second meetup is happening tomorrow. My experiment produced a result I didn't expect.
One data point is not sufficient to draw conclusions, but this result suggests that further experiments should be tried. It may just be that many cities have reached a critical number of active LessWrongians and regular meetups can start happening. Which is trivially of positive net effect.
Therefore, I would encourage people to consider getting out there and trying to set up meetup groups in their areas. But since this requires individuals actually willing to assume the role of organisers, this may not be as easy as it sounds. Fortunately, there is a document currently in development that aims to provide some help with this: http://lesswrong.com/r/discussion/lw/bak/draft_how_to_run_a_successful_less_wrong_meetup/. But there might be something else that can be done - a pioneering approach.
If you have some experience of attending/organising LW meetups, next time you are in a different city (even if only for a couple of days!) try to devote a couple of hours to organising a meetup there. Be a "pioneer". Here is what I learnt from the meetup in Budapest: