Face-to-face social interactions among strangers today are becoming increasingly rare as people turn towards computermediated networking tools. Today's tools, however, are based on the following assumptions: increased information encourages interaction, profiles are good representations of users to other users, and computer-mediated communications prior to face-to-face meetings lead to better outcomes. This paper describes CommonTies, a gentle technological nudge in the form of a wearable accessory, that encourages immediate, face-to-face, organic social interactions among strangers at conferences. By not exposing any profile information, CommonTies preserves an element of mystery and enables selfdisclosure of information through conversation. We evaluate our system through a field study at a three-day research conference - CSCW 2014. We find that despite our informationscarce design, users were willing to interact with strangers and 74% of the interactions initiated by CommonTies were reported as novel and useful.