In this paper we describe the development of a platform that enables us to systematically study online social networks alongside their real-world counterparts. Our system, entitled Cityware, merges users' online social data, made available through Facebook, with mobility traces captured via Bluetooth scanning. Furthermore, our system is constantly growing, since it enables users to contribute their own mobility traces. In addition to describing Cityware's architecture, we discuss the type of data we are collecting, and the analyses we intend to carry out. Keywords Social networks, bluetooth, Facebook, mobile phones. ACM Classification Keywords H5.m. Information interfaces and presentation: Miscellaneous.