The ever-increasing amount of media items on the World Wide Web and on private devices lead to a strong need for adequate indexing and search techniques. Trends such as personal media archives. social networks, mobile devices with huge storage space, and networks with high bandwidth capacities make distributed solutions and in particular Peer-to-Peer (P2P) lnformation Rertrieval (IR) systems attractive. On the other hand, when designing effective media search applications, various search criteria have to be addressed. Hereby, geospatial information is frequently used as well as other criteria, such as text, audio or visual media content, and date and time information.
In this chapter the authors outline how collections of georeferenced media items can be indexed and searched in P2P IR systems. They discuss different types of P2P IR systems and focus in detail on an approach based on collection description and selection techniques. This approach tries to adequately describe and select collections of georeferenced media items. Finally, the authors discuss its broad applicability in various application fields.