Why Malkovich? Perhaps because, in his brainy-balding, downtown-anonymous way, he himself possesses a kind of virtual mystique; he's like an ordinary guy who has taken on the existence of a star. (No one in the movie can remember what films he's been in.) Spike Jonze, the director of ''Malkovich,'' is a celebrated creator of music videos who has often toyed with point-of-view imagery, and here he uses it to stretch and contort your perceptions in funny, exhilarating Silly Putty ways.
Craig, who's married to the sweet, rumpled Lotte (Cameron Diaz), meets a diamond-hard office vixen, Maxine (Catherine Keener), and falls in love with her. Before long, the characters are using Malkovich as a host body; the two women begin to have sex with each other through his consciousness, layering their identities on top of his. Are we watching a mad-dog fame fixation? Subterranean gender bending? Actors cast so far against type that their images are turned inside out? Yes, yes, and yes, and more besides.
''Malkovich'' has a bustlingly evocative yet deadpan pretzel-logic style, so that you never question the reality of what you're seeing. Jonze, working from Charlie Kaufman's intricate script, is like a dada prankster playing metaphysical magician. I wouldn't want to give away the film's wilder twists, but I'll just say that it makes identity surfing seem as conventional as breathing, and that it has room for everything from a hilariously self-mocking Charlie Sheen to the spooky beauty of Craig's puppet shows -- another form of ''being'' someone else.
The movie, a bravura act of dream-ride showmanship, takes off from a world in which personality has become fluid, ironic, and multistranded, and in which all of us are built out of images floating around inside us. Welcome, Jonze seems to say, to your own role-scrambled head: the 21st-century Wonderland.