Our paper on Crowds, Bluetooth and Rock’n’Roll: Understanding Music Festival Participant Behavior is available in arXiv. At a large music festival (8 days and 130,000+ participants) we applied Bluetooth sensing to discover Bluetooth-enabled mobile phones carried by the participants, which enabled us to observe patterns of behavior in terms of participant mobility and offline social interaction. An overall summary of the mobility data collected during the 8 day festival is shown below.

A nice popular summary of the article was made by MIT Technology Review in Music Festivals, Bluetooth Monitoring and the Behavior of Crowds.