Abstract. Although mobile hand-held devices (MHDs) are ubiquitous today, little is know about how they are used--especially at home. In this paper, we cast a first look on mobile hand-held device usage from a network perspective. We base our study on anonymized packet level data representing more than 20,000 residential DSL customers. Our characterization of the traffic shows that MHDs are active on up to 3 % of the monitored DSL lines. Mobile devices from Apple (i. e., iPhones and iPods) are, by a huge margin, the most commonly used MHDs and account for most of the traffic. We find that MHD traffic is dominated by multimedia content and downloads of mobile applications. Key words: Mobile Devices, iPhone, Traffic Characterization