A system to receive data indicative of physical location from a first computing device and to associate an event with the physical location, the event occurring at the physical location and including the physical presence of two or more entities. The system further to receive registration information from one or more entities that are associated with the event and to generate, using the registration information, a data object to enable a first entity of the one or more entities and a second entity of the one or more entities to exchange one or more items while the first entity and the second entity are both physically present at the event. The system additionally to publish the data object to a second computing device based on a participation criteria, the second device being operated by at least one of the first entity and the second entity.