Having just returned from Paris, where she spent a week putting the finishing touches on the 100-day shoot of her latest movie, Nancy Meyers is jet-lagged. ''I can't sleep,'' she says, calling at a dusky 7 a.m. ''I'm happy somebody's up with me.''
Who could sleep? When your last film (''What Women Want'') grossed $183 million, making it the biggest live-action hit ever directed by a woman, how do you follow up? Meyers called Jack, of course. Her romantic comedy features Nicholson (for whom she wrote the part) as an aging record exec with an eye for younger women who unexpectedly falls for the playwright mother (Diane Keaton) of his new girlfriend (Amanda Peet). Turning the triangle into a square is Keanu Reeves, as a doctor who also has affections for Mom. ''It's one of the best romantic comedy scripts -- or any script -- I've read in a long time,'' says Reeves, whose ''Matrix Revolutions'' will still be in theaters when this opens. ''It's smart and personal and relevant and funny.''
Another thing that could be keeping Meyers awake? Memories of a night in July when protesting French workers took over Paris' Pont d'Arcole, where she was shooting the final scene. The result was a one-day delay and comical reports of a sunglasses-sporting Nicholson shouting through a megaphone, en français, ''The struggle continues!'' ''I was in Jack's trailer,'' Meyers says, when her (non-striking) crew ''knocked on the door and said, 'You shouldn't come out now -- the bridge has been taken over.' Jack went out to talk to everybody -- he's a big union guy. But I don't think he persuaded them.''
Not that Nicholson's trademark charm is wearing off. True to form, the three-time Oscar winner helped make for an awfully fun shoot. ''He's devilish in the best way possible,'' says Peet. And when Nicholson wasn't around, the distaff ensemble -- which included Frances McDormand as Keaton's sister -- got along without him. ''In between working we could sit around talking about liposuction,'' says Peet. ''There was definitely some girl talk going on.''
The Killer Moment Nicholson accidentally catches Keaton undressing. Says Peet: ''It's the funniest goddamn thing I've ever seen!''