... We describe a Data Inventory Service (DIS) that uses Virtual Observatory protocols to discover, organize and present astronomers with a rapid precis of what is known about a given region of the sky. The DIS queries a dynamic registry of VO resources to discover potential sources of information, queries them on behalf of the user and then saves and organizes the results for display. ... Since the DIS caches results from services, users can quickly browse catalog and image results. ...