A core functionality of any location-aware ubiquitous system is storing, indexing, and retrieving information about entities that are commonly involved in these scenarios, such as users, places, events and other resources. The goal of this work is to design and provide the prototype of a service-oriented middleware, called Geocon, which can be used by mobile application developers to implement such functionality. In order to represent information about users, places, events and resources of mobile location-aware applications, Geocon defines a basic metadata model that can be extended to match most application requirements. The middleware includes a geocon-service for storing, searching and selecting metadata about users, resources, events and places of interest, and a geocon-client library that allows mobile applications to interact with the service through the invocation of local methods. The paper describes the metadata model and the components of the Geocon middleware.