(I don't mean to seem querulous, but) Probably, or plausibly? The latter is not bad, but making a resonance into a probable connection requires work applied to that specific task.

This is likely not the best place to introduce my personal project, but it should have some bearing on the topic at hand.

I am in the process of building a website at http://human-survival.org which is specifically devoted to the discussion, cataloging and eventual reduction of existential risk. I would expect there to be other sites, like mine, which focus more narrowly on the focus of a particular topic which sits well with rationalists.

This means that I'm suggesting you look not just outward at groups which border "rationalism" on a hypothetical map of different "isms" but also inward at groups which are partly or wholely covered by your philosophy.

Since this is my first post, a bit of backgrounding on my site: I know that species existential risk is a frequent topic on LessWrong, although it seems LW is more widely pointed at rationalism as a whole. My intent is to be more pragmatic and scientific (ruthlessly so) on this single topic of making the human species as likely to survive as possible.

I believe my structured wiki (sample pages being researched and written right now) to list out potential threats to survival is of particular benefit. I'm happy to reach out to the LessWrong community and invite continuing cross-pollenation between the sites.

I think it would be useful to have a compatable template for interacting with related communities such as my human-survival.org, so that they can be listed and described and discussed freely and equally.

I am pretty into the skeptic community and i do wish more people had heard of less wrong. I think it would be a great idea to try to make an outreach effort to those groups. For instance the skeptics usually want to improve their rationality (the other groups you list might). I know the biggest skeptic podcast talks about things related to rationality quite often. Although I am pretty disappointed at the lack of knowledge of bias, heuristics and things like bayes theorem amongst the people who i have talked to in the skeptics community

Not for groups, but for individual people. When I talk about topics of general interests for rationalists with someone else, I often introduce them to less wrong. I tell them something along the lines of "There's a community of like minded people who likes to discuss similar topics on LessWrong.com".

I think something similar, i.e. organic recommendations can work for larger groups, you just have to use a different format. One idea would be to give a presentation and then add a final slide recommending to check out the website.

One of the primary problems with the rationalists, humanists, atheist, skeptics, etc. is that there is no higher level organization and thus we tend to accomplish very little compared to most other organizations. I fully support efforts to fix this problem.

There is an online stoic community that even has a map with the locations of members.

For those not deeply read on the subject, Stoicism is relevant because the belief system roughly holds (1) that the only unqualified good thing is personal virtue, (2) that most human mental states (like emotions and preferences in addition to declarative cognitive content) are in some sense states of belief, and (3) that virtue consists in having certain and true beliefs (broadly construed) about what is good. I'm emphasizing points that might interest LWers (for example Stoics had an interesting angle on akrasia) and leaving out details for succinctness.

I've been playing with the idea of sending invitations to some people on the New Stoa map when I know about LW meetups happening near them that would be friendly to their attendance. I've never taken steps on this thought and have no data on the feasibility or value of this effort, but it seems worth putting here in case someone else wanted to try it :-)

Maybe Unitarians are sufficiently different from place to place, but the ones in Northern Virginia I've visited (due to claims like yours from others in the past) are no more compatible with LW than Buddhist temples or political conventions. That is, they have been orthogonal, at best, to LW interests.

Do you have first-hand experience with Unitarian churches that differs? If so, in what way(s) they seemed compatible, other than "we don't insist on belief in gods and we'd like to be good people and have a sense of community"?