With his fine solemnity and vague air of being desperately uncomfortable in his own skin, Keanu Reeves is a perfect choice to play the preachy space alien Klaatu in this millennial update of the 50s sci-fi classic. Some popcorn never gets stale, and the opening stretch, when the visitor arrives on earth and calmly dresses down mankind, is great fun. But screenwriter David Scarpi has drained away much of the sentiment—even the little boy befriended by Klaatu treats him with dread—and the original movie's climax, an endearingly corny homily about the necessity of peace, has been replaced by a pointless tsunami of digital effects. Scott Derrickson directed; with Jennifer Connelly, Kathy Bates, John Cleese, Jon Hamm, and Kyle Chandler. PG-13, 104 min.