The widespread use of digital mobile devices has accompanied a range of new practices, as well as hopes, fears, and prognostications regarding the relationship between humans and technologies. This dissertation investigates the study of human/technology relationships and corresponding conceptions of agency. Traditional approaches to studying communications technologies rely on distinguishing individuals from devices, thus reflecting an Enlightenment and empiricist tendency that isolates and places individuals or devices at the center of effectivity. To address the inadequacies of this approach, the term digital mobility calls attention to the dispersion of agencies constituted by humans and devices rather than the movement of humans or devices through geographic space. After presenting the theoretical and conceptual basis for the study, the dissertation focuses on two component practices which comprise digital mobility as an assemblage of dispersed agency. Historical formations of miniaturization produce objects as transitive rather than whole and complete, thus critiquing empiricist conceptions of objects as unitary wholes. Whereas crafting miniatures relied on a referent, the generalizable process of miniaturization discards the referent and instead shrinks capabilities. Likewise, historical formations of remote control both affirm and negate Enlightenment conceptions of individual agency. While remote control allows the distant manifestation of individual command, its production as a nonhuman capability renders devices as active enabled through their human counterparts. Drawing from the concepts of transitive and active objects, the study then focuses on three contemporary agencies as digital mobilities and their articulations with broader formations. The dissertation concludes by discussing the implications of digital mobility for the study of communication and agency, as well as offering directions for future studies.