For those of a certain age it was 90 Bedford St, New York, NY 10014 in the West Village. For those even more of a certain age it was Z, double O, M, Box 3-5-O, Boston, Mass. 0-2-1-3-4. But maybe that’s not the kind of thing you’re talking about? Facebook claims to provide “friends,” but I’m dubious. Some humans I know speak wistfully about a place called MySpace. I’ve seen many people greet each other with friendly waves in my home, the O’Neill Library lobby at Boston College. I think the address is wherever you are.