In Thirteen, Holly Hunter and Co. argue over, well, a lot. But in one scene the family can't decide which movie to see: John Cusack's war drama Operation Kandahar or Jack Black's wacky ''pig movie,'' The Misadventures of Ezekial Balls. Unfortunately (or, perhaps, thank God?) for real-life moviegoers, neither will be at a theater near you. ''It's the one laugh in the movie,'' says Thirteen's director-cowriter Catherine Hardwicke (above), who says an intern came up with the faux titles. ''We didn't want [real films] to look ancient by the time [Thirteen] came out.'' She persuaded pal Cusack to donate a publicity still; Black then did the same. We're told neither actor has seen the angsty indie, but Hardwicke thinks Black could have a Ball with his project: ''People have said, 'Oh, yeah, let's make that movie next!''' Sounds better than, say, Shallow Hal II.