Ron Livingston -- who appeared in two episodes of Sex and the City last season as Carrie's crush, writer Jack Berger -- will be back when the show returns in mid-June. ''We're picking up right where we left off, when we said we were going to have a real date,'' says Livingston. Will Jack be the one to make Carrie forget all about Mr. Big? ''What I do know, I can't tell.''... Justin Theroux, who played a sleazy director in Mulholland Drive and next appears in Charlie's Angels 2, will guest on the June 1 season finale of Six Feet Under as a neighbor of Rachel Griffiths' Brenda.... Now here's the kind of TV reunion special we'd like to see: Roseanne wants to shoot scenes for her upcoming ABC reality show from the set of Best Damn Sports Show Period, the Fox Sports yakfest cohosted by her ex-husband Tom Arnold. ''She called Fox about bringing a crew down,'' says Arnold, who likes the idea. ''Apparently, she asked the producers how the hell they could give me a show and not give her one. Which is a good question.''