Remember "My disk?" That is, your floppy disk, the one that you stored everything on? If you're about my age (I'm 34) and you used computers in the 80s and very early 90s, you probably had a "my disk" disk. I was talking to my sister today and she was telling me about her disk. "It had the OS [probably Mac OS 6.0.x], my copy of WriteNow (awesome word processor from olden days) and all my files on it," she pointed out, "and it wasn't even an HD disk! It was a regular old DD 800K disk!"
I think we need to get back to the days of my disk. Instead of a floppy, my disk will now be a flash memory card. And instead of 800K, my disk should be about . . . well, a terabyte would be ideal but maybe that's a little ambitious. I've heard they're talking about 32Gb flash memory cards now.
One of the advantages of my disk is that I never have to worry, "Oh, which computer did I leave that file on?" I carry my disk around with me in my phone most of the time. When I'm on a computer, I simply pull my disk out of my phone and plug it into the computer I want to work on. I boot from my disk, not from the machine's internal hard drive. My disk can boot from any OS I want to use. In my case, those are some flavor of GNU/Linux, Mac OS 10.x, and, if absolutely necessary, Windows. My disk also contains any software I want to use, plus all of my files. It can be backed up seamlessly and quickly (automatically when I plug it into my home machine, perhaps) so if I lose my disk, I don't lose all my stuff.
Alas, my disk is not yet a reality. But I'm looking forward to the triumphant, imminent return of my disk.