Mobile social software is currently designed and conceived to afford serendipitous social interactions in densely populated urban environments. In this paper, I argue that these systems create a more homogeneous representation of the city by encouraging users to socialize more exclusively with those they already know and by privileging a type of urban experience based on consumption and entertainment. I describe several design strategies drawn from the arts that might help these systems offer a more heterogeneous view of the city. Author Keywords Mobile social software, homophily, tactical intervention, critical design, interpretation ACM Classification Keywords H5.3. Information interfaces and presentation (e.g., HCI): Miscellaneous.