This work presents a communication pattern for high mobile ad hoc networks. En-passant communication uses the short interaction period of passing devices to efficiently synchronize the information of each device. This is achieved by creating peer-to-peer overlays of interest domains. Missing information is determined by exchanging profiles first. As example application UbiQuiz is presented, a mobile quiz application. It exchanges questions using the en-passant communication pattern. UbiQuiz has been implemented, tested and evaluated within a simulation and on real devices.