Fascinating article on The Future Of The File System, wandering through file storage and associative linking [via CamWorld]. Interesting ideas about looking at your email mailboxes as divided in folders "threads", "from", "date", etc. And a good point that there really shouldn't be folders at all, just virtual groupings -- although I'm sure this wouldn't be any harder to use than the current hierarchic system, objectively, the momentum and experience people have in using an already pretty obtuse system might preclude switching.
I've wanted to do this for a while: browse MP3s, or email, or a MySQL database as easily as a dedicated MP3 player, or email or database client, but as part of the file system. Why should that be so hard, and why aren't OS designers making the effort? The fact that people are having to design these alternative browsing systems and that they can't rely on the filesystem indicates to me that the current OS is reaching the end of its life.