Although the Internet takes us everywhere in cyberspace, it usually requires us to be seated behind a desk. In contrast, the cellphone lets us walk through the world, fully connected. Cellphone explores the history of mobility in media from books to cameras to transistor radios to laptops and examines the unique impact of a device that sits in a pocket or palm, and lets us converse by voice or text. The impact cuts both ways, and obligates as well as liberates: the device that allows us to call anytime, anywhere allows us to be called anytime, anywhere. Cellphone considers how this new dual edge of accessibility has transformed journalism, restaurants, public transport, automobiles, romance, parent child relationships, and indeed all walks of life, trivial and profound. Like an organic cell that moves, evolves, combines with other cells, and generates, the cellphone has become a complex sparkplug of human life.