This book explains how mobile computer usability is shaped by the increasing integration of personal circumstances in organization. It represents an attempt to conceptualize an alternative model of mobile computer usability. It is motivated by the author’s conviction that we do not yet have an adequate understanding of this concept because we have not taken seriously the transformation of human personality by the co-evolution of organization and ICTs. The author argues that the transformation has resulted in a human personality whose personal and organizational activities are characterized by strong continuities between them. This characterization reflects a new kind of personality of the worker, and is a critical determinant of mobile computer usability. The word ‘organizational’ is used to describe this kind of personality – hence an alternative organizational personality perspective on mobile computer usability. This perspective suggests that a mobile computer is more usable to a person than another one because of its satisfaction of both his personal and organizational motives, which are in turn shaped by the co-evolution of organization, technology and personality.