The present study examines how mobile practices of social-media use are integrated into individuals' everyday lives as a way to manage their relationships. Mobile communication technologies and social-media use intersect in people's everyday communicative practices, allowing individuals to engage in continuous interactions that take place on the move and are embedded in the dynamic physical and social contexts of everyday life. In this context, this qualitative and exploratory research examines how mobile social media fit into the ways young adults manage their personal and social relationships on the move and in contexts of limited movement. In doing so, this study extends the research within interpersonal communication and relationship-management traditions by connecting this line of inquiry to research on mobile communication, social media, and the sociology of mobilities. It considers the ways in which these perspectives challenge, and can help expand, traditional approaches to interpersonal communication. Structured as a comparative analysis, this study is focused on young adults who live in Concepcion, Chile, and the Triangle area of North Carolina in the United States. My fieldwork employed a mobile and multi-sited ethnographic approach, including interviews with 36 young adults (20 Chileans and 16 Americans) and ethnographic observations in both Raleigh and Concepcion. The methods included a shadowing process, which consisted of following and observing participants while they moved through their daily activities. The aim of this exploratory study was to collect naturalistic data to illuminate the complex processes through which mobile communication technologies and social media are woven into participants' everyday social interactions. Given the increasingly complex media ecology within which individuals carry out their activities and social interactions, these methods made it possible to observe and analyze emerging practices naturalistically, within mobile social contexts. By examining the micro-contexts of mobile social-media practices, this research shows how individuals experience continual connectedness to others in a flow that merges online and offline interactions and blurs the boundaries between interpersonal and mass communication. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]