If the group still feels like a part of the (LW-related) rationalist community, they should be willing to write something about them on LW, once in a while. Maybe this should be encouraged by some kind of regular “Rationalist Subgroups Report Thread”, where each group would briefly describe themselves, and say what they did during the <whatever would be the interval of that Thread>.
Then this Thread would act as the place to collect information; and perhaps it could have a related wiki page.
If the group still feels like a part of the (LW-related) rationalist community, they should be willing to write something about them on LW, once in a while. Maybe this should be encouraged by some kind of regular “Rationalist Subgroups Report Thread”, where each group would briefly describe themselves, and say what they did during the <whatever would be the interval of that Thread>.
Then this Thread would act as the place to collect information; and perhaps it could have a related wiki page.