"Grey Belt" - combines the "we are all aspiring rationalists" notion (white belt, also activates the dojo node) with a significant color word - grey matter.
"Possible Minds" - because that's an Eliezer catchphrase, but also a succinct statement of the intent: to explore the space of possible minds, although only in a tiny region to start with. (You may view the link with SI - exploring the same space much farther out - as a bonus or as a problem.)
"Hedgefox". Not 100% original, but combines a prediction reference (cover of Tetlock's book), references to thinking styles, and the notion of cognitive diversity.
Upvoted for Grey Belt. The other two are terrible. Grey Belt on the other hand, is a clear image, very short, and has the added advantage of (possibly) being immediately understood by ~1/2 of the general population (at least next to a good logo).
The Singularity Institute wants to spin off a separate rationality-related organization. (If it's not obvious what this would do, it would e.g. develop things like the rationality katas as material for local meetups, high schools and colleges, bootcamps and seminars, have an annual conference and sessions in different cities and so on and so on.)
We can't think of a name for this organization.
We can't think of any names that seem good enough to be audience-tested.
We don't have any ideas good enough that we'd want to mention them in this post.
Help.