This book applies sociolinguistic methodologies and theories to mobile communication. Have wireless mobile communication technologies changed the way people talk to one another? What does it mean to be able to speak or write to anyone, anywhere, 24/7/365, and get an immediate response? And what does the current profusion of these technologies mean for the study of language in social life? This volume takes a global perspective and provides readers with a nuanced, ethnographically-informed understanding of mobile communication and sociolinguistics. It explores a wide range of digital applications, including SMS, email, Twitter, Facebook, YouTube, chatting, blogging, Wikipedia, Second Life and gaming. It raises important questions about the nature of language, the roles of multimodality and intertextuality in creating meaning, and the realities and consequences of digital linguistic inequality. It explores the formation of virtual communities, ways of online socialising and the performance of the digital 'self'. Based on a multicultural and multilingual approach, it gives a comprehensive and intriguing overview of digital communication. It contains a glossary of relevant terms. It provides a global context which highlights common trends and practices in mobile communication. It utilises extensive original multilingual data within case studies. It discusses new research insights and innovative interdisciplinary approaches.