Form your own private, by-invitation, undiscoverable group. Friends and colleagues are the obvious place to start, and not too large. I've belonged to one for

Form your own private, by-invitation, undiscoverable group. Friends and colleagues are the obvious place to start, and not too large. I've belonged to one for almost 20 years. I think the group has varied between 10 and 20 people, a few have come and gone (and come back). We use an email list, use whatever you like.