Plot: Barack Obama's inauguration is marked with a trip to Harlem. Plus Ed Burns, co-writer of the new president's favourite TV show, The Wire, on his Iraq war account Generation Kill, Roberto Saviano on Gomorrah - his book about the Naples mafia, and now a film tipped for an Oscar nomination - and backstage with Armando Iannucci as he gears up for the first night of satirical opera Skin Deep