OK" as a word accepts proposals, describes the world as satisfactory (but not good), provides conversational momentum, or even agrees (or disagrees). OK as an object, however, tells a story of how technology writes itself into language, permanently altering communication. OK is a young word, less than 200 years old. Today it is spoken and written by nearly everyone in the world. Drawing on linguistics, history, and new media studies, Michelle McSweeney traces OK from its birth in the Penny Presses through telephone lines, grammar books, and television signals into the digital age.