The Less Wrong meetup in Columbus, OH is very oriented toward popularizing rationality for a broad audience (in fact, Intentional Insights sprang from this LW meetup). We've found that doing in-person presentations for secular groups is an excellent way of attracting new people to rationality, and have been doing that for a couple of years now, through a group called "Columbus Rationality" as part of the local branch of the American Humanist Association. Here's a blog post I just published about this topic.

Most importantly for anyone who is curious with experimenting doing something like this, we at Intentional Insights have put together a “Rationality” group starter package, which includes two blog posts describing “Rationality” events, three videos, a facilitator’s guide, an introduction guide, and a feedback sheet. We've been working on this starter package for about 9 months, and finally it's in a shape that we think it's ready for use. Hope this is helpful for any LWs who want to do something similar with a secular group where you live. You can also get in touch with us at info@intentionalinsights.org to get connected to current participants in “Columbus Rationality” who can give you tips on setting up such a group in your own locale.