Interest in network-centric programming and applications has surged over the last few years due to the exponential growth of the Internet and the widespread popularity of the WWW. In response to this, new techniques, languages and paradigms have evolved to facilitate the creation of such applications. Perhaps the most promising among them is the mobile agent paradigm. However, in order to take advantage of this new technology, several issues must be addressed, such as naming and locating mobile agents. These two services are necessary for efficient agent management. In this paper we discuss these issues and their impact on agent design. Several abstractions are introduced that allow an easy and flexible integration of these services in agent-based applications.