There are a few drawbacks to using directories to organize your files - they can be slow and difficult to move between remote machines, and there's no means of security.

It would be nice to be able to zip up the directory into a "book" with a single click - the book could now be moved anywhere as a single file and reopened elsewhere. Books could have locks on them, so that you could lock and unlock them with a password, PGP key, etc.

After having this idea, i came across a company called OnTrack with a product ZipMagic that comes pretty close to what i had in mind.  I'm also not sure if you can move a ZipMagic file from one machine to another with no complications.

In Q1 2000, i tried the latest version.  It claimed to work with Windows 2000, but it didn't.  Oh well.