This paper reports ethnographically informed observations of the use of mobile phones and text messaging services amongst young people. It offers a sociological explanation for the popularity of text messaging and for the sharing of mobile phones between co-proximate persons. Specifically, it reveals that young people use mobile phone content and the phones themselves to participate in the practices of gift exchange. By viewing mobile phone use in this way, the paper suggests a number of possibilities for future phone-based applications and supporting hardware.