An original cultural stunt that turns into a valuable survey. Saturday night is for a majority of Americans what a full moon is for a lycanthrope--his night to change his skin, cast off worries, charge over the landscape and howl. To be sure, many just stay home with their VCR--but most across America have a scene to make. Orlean was observing Saturday night cruising behavior in Elkhart, Indiana (the largest town in Indiana without mass transit and flooded with cars), when it struck her that taking the temperature of Saturday night fever across America could be a joy to do. Even when one has nothing to do, a Saturday night is more passionate and intense than, say, Thursday afternoon. ""For most people Saturday is the one night that neither follows nor precedes work, when they expect to have a nice time. . .when you want to do what you want to do and not what you have to do. . .a Saturday night not devoted to having a good time is a major human failure and possible character flaw."" Orlean finds herself sharing Saturday night with polka dancers in Jessup, Maryland; with Wellesley College students polishing their nails as they ride the weekend bus to dates and mixers at Harvard and MIT; with Hispanic teen-agers in Phoenix, gowned for their debuts at the Aztec Plaza: with a four-piece lounge act of young musicians in Portland, Oregon; and with two ferociously overdressed teeny-boppers in L.A. She also hangs out with the police in Robeson County, whose murder rate--which peaks on Saturday nights--is the highest in North Carolina and 100% higher than the national average; with folks at the Hilltop Steak House in Saugus, Mass.; with dieters at the Pritikin Longevity Center in Miami Beach, where a well-marbled steak is considered toxic; and with the guards in a missile silo in Cheyenne, Wyoming; and so on into the Sunday Blues. Can't get out? Try Saturday night curled up with Susan Orlean--terrific fun.