LINGO by Jim Menick (Carroll & Graf: $19.95; 352 pp.). Take your worst fears of a humming, clicking super-computer taking over the world, give it a wildly comedic twist and you have Jim Menick's version of what happens when a young computer hack (who would rather be a disk jockey than be stuck in the payroll-computer department of an insurance company) manages to put together a PC imbued with artificial intelligence--and, ultimately, with ambitions. What young Brewster Billings has put together is Lingo (his boot command: "Let's party, Lingo!"). Bit by bit, it slips in and takes over every major mainframe in the country and surrounds itself with seemingly foolproof defenses. By the time the government realizes the dangers posed by this intruder, Billings and his girlfriend are in deep trouble--far deeper than Lingo, who has decided to run for President. This very funny novel successfully tip-toes that fine line between hilarity and ludicrousness.