This document summarizes a novel application called Live Social Semantics that integrates data from the semantic web, online social networks, and an RFID-based face-to-face contact sensing platform. It tracks face-to-face contacts between conference attendees using RFID badges, builds profiles of attendees' interests by linking their social media data, and allows attendees to view their connections to other attendees. The system was tested at a conference where over 300 attendees participated, and future work is proposed to improve interest profiling and support additional applications using the social interaction data.