A three-year qualitative study of the use of mobile e-mail devices in a footwear manufacturer focused on the experience of two occupational functions. Evidence suggests that congruent frames of heterogeneous communication practices enabled one group to develop communication norms that circumvented the trap of constant connectivity, while assumptions of homogeneous communication practices in the other group led to expanded accessibility and erosion of personal time. This study examines how such alternate trajectories of use emerged and discusses the key dimensions of difference between groups--identity, materiality, vulnerability, and visibility--that help account for these differences. In introducing the distinction between homogeneous and heterogeneous trajectories of use and explicating how such trajectories emerge, this study offers several theoretical insights: it suggests that there is a distinction between the congruence of technological frames of reference and the content of these frames; it provides an explanation for why groups might enact mobile communication technologies in a manner that does not lead to constant connectivity; and it highlights how shared assumptions of heterogeneity relate to systems of social control. [ABSTRACT FROM AUTHOR]