I've been thinking a lot about meta-information. I've been perusing standards such as RDF, thinking about how to apply them functionally. A lot of the work has been largely theoretical, with a lot of the people aiming toward making computers sentient beings. Not quite, but almost.
Anyway, I've been thinking of practical uses of metadata repositories and RDF-like things.
I've come to the conclusion that GNOME needs to incorporate meta-data into it's API and GUI, and doing so will enable it's users to combine information like no other system.
Let's start with the basics. Let's say I'm running a project. I want to know all of the information that has come in for this project in the last 3 weeks. Current tools only let me query the filesystem. However, if applications were allowed to store metadata centrally, a user could search information within emails, files, their calendar, and any other tool that supported metadata. The user simply has to tag (or set up rules to autotag) information that comes in as relating to the project, and then if they need to search for such information, they can do it all from one place.
Anyway, I've got some more ideas on this, and I will post them as I have time.