I took a walk this morning, around my neighborhood. You should understand, in some ways I am a very typical urban dweller.  I don’t know my neighbors.  We don’t hang out together, we don’t have each others’ phone numbers, we aren’t pals.  Nothing deliberate, just a product of the car and the phone and the pace of our lives.  When we moved into this neighborhood a quarter-plus-century ago, we would take evening walks and see many older residents sitting on their porches.  Some would wave and smile.  I finally realized that some of them, at least, were indulging a practice from a faded era.…