THE REVOLVING DOOR SPINS: “Stephen Barr, who authored The Federal Diary column for several years, this week joins the Labor Department as a top public affairs official. . . . The move makes Barr a member of the Senior Executive Service, a corps of senior federal employees that Barr covered from 2000 to 2008 as author of the Diary, a column widely-read by federal employees nationwide that remains one of the longest-running features of the Post.”