By exploring the newly identified phenomenon of giving mobile phones personal nicknames, the present article contributes with knowledge about the socio-material relationships between mobile phones and the self. Building on previous research, the study examines typologies and social functions of mobile phone nicknames. The study shows how the respondents’ use mobile phone nicknames for interpersonal communication and group identity practices, but also to symbolize private relationships with the device in which no other human than the name-giver is involved. By examining the respondents’ use of the mobile phone, I argue that the role of the mobile phone in the lives of individuals is more complex than previously recognized, not only functioning as mediator or icon of the self, but also as companion to the self.