Virtual Observatories: Are We Virtually There Yet?

Virtual observatories are tools for simplifying access to and use of astronomical data from an increasing number of data sources of rapidly growing volume. Now that a variety of virtual observatory development efforts are under way around the world, a cursory review of the efforts outside solar physics, and an only slightly more detailed consideration of those within, demonstrates a commonality of conceptual model if not of approach or application. The linkages among virtual observatories optimized for different scientific communities present an interesting challenge to the designers: should virtual observatories be designed for the most expert users? For the least? For everyone? It is too early to provide definitive answers, but examination of current efforts does offer some clues.