Ubiquitous and pervasive systems rely on a highly dynamic and heterogeneous software / hardware infrastructure. A key factor in dealing with this diverse and sophisticated environment is the ability to 'map' all entities into a robust, scalable and flexible directory mechanism, able to maintain and manage a large number of heterogeneous components while acting not only as an information repository but also to be able to associate individual and component-specific information. This mechanism should enable the ubiquitous service designer to use a global directory service which can answer queries in an intelligent manner and relieve both the user and developer from tedious procedures of querying databases. In this paper we elaborate on the benefits gained by incorporating semantic technologies in the area of ubiquitous and pervasive computing as a means of meetings these needs. We base our experience on a case study of software component exchange among 3 different vendors which demonstrated the flexibility of adopting such a mechanism of ontology registry.