>We've got movies and Madonna this week on cable. From Aug. 1 to the end of the month, the Movie Channel is showing 418 (count 'em) different films in 60 different "festivals." Each festival highlights an actor (there's a Jimmy Stewart triple feature on Aug. 2) or a genre (Aug. 11 has films about show biz). They are literally showing A (... All the Marbles) to Z (Zelly and Me.) It's enough to leave you breathless! Which brings us to Madonna and a taped concert from her Blond Ambition Tour. HBO broadcasts—one night only—Sun., Aug. 5, 9 P.M. ET.