*Reuniting: Former real-life couple Jack Nicholson and Anjelica Huston are back together-on screen, of course. Huston will play Nicholson’s ex-wife in The Crossing Guard, a drama to be directed by Sean Penn…. * Prepping: * Cyberpunks must be very psyched about the upcoming Johnny Mnemonic. Based on a William Gibson short story, the film will feature Christopher Lambert, Ice-T, Dolph Lundgren, and a porpoise. Eighties art-world star and music-video director Robert Longo will be making his feature debut behind the camera…. * Shooting: All that polo will help Tommy Lee Jones look suitably athletic in the title role of the Ty Cobb biopic Cobb, soon to begin filming in Lake Tahoe, Nev. Ron Shelton, who hit a homer with 1988’s Bull Durham, is directing.