An upturn for spring, this is a bright, joking conversation piece in which cartoon-like illustrations accompany the phrases that divide the sheep from the goats. Free-wheeling classifications are capricious on both sides and happily demolish affectations while introducing giddier ones; they establish madcap standards for IN and a balanced ostentation for OUT and ""everything that is not IN is OUT."" Food, books, pets, movies, places, men and women's clothes, travel, art, love, words, celebrities, classic OUT things, greeting cards, etc., are posited on one side or the other, leaving the innocent reader busily trying to climb out of a rocky quandary -- is he IN or is he OUT. Bound to amuse, this is agile, erratic systematizing which should catch some passing, fancy interest --along parlor, personality game areas or as an unpredictable diversion. This team roused the readers of Esquire when their aribitrary material appeared in it and Russell Lynes (himself an OUT) genially introduces them in book form. Might be the tres chic of the week.