James, note the "some sort of integrated encryption with a keyphrase" bit? Integrate some level of security into the actual hardware spec, so you don't have to worry about somebody's system not having the right kind of software to read your encrypted stuff.

And you'd always want backups, of course. Automated backup software for your keyring-drive is the sort of "value-added" stuff that implementors could use to make extra profits and differenciate their products from others.

Of course, this sort of technology isn't terribly useful unless it's already ubiquitous, which makes getting it into common use a bit problematic. Oh well. Nice pipe dream, anyway.