Earth allows you to find files across a large network of machines and track disk usage in real time. It consists of a daemon that indexes filesystems in real time and reports all the changes back to a central database. This can then be queried through a simple, yet powerful, web interface. Think of it like Spotlight or Beagle but operating system independent with a central database for multiple machines with a web application that allows novel ways of exploring your data.
R. Kent. Proceedings of the 17th International Conference on Conceptual Structures (ICCS 2009), Volume 5662 von Lecture Notes in Computer Science, Seite 201-218. Springer, (2009)