How portable can an operating system get, well it depends on what you think portable means. If you think that it means that you can carry it around with you, then you would not be far wrong.
But, When I talk about portable and in this particular case, I am refering to putting you O/S in your wallet on something smaller than a stamp.
As I write this I am looking at a M2 USB Adapter with a 2 GB micro disk plugged in the side, pretty amazing I think.
With this tool, I can take my computer anywhere I want to, with my O/S on one stick and my files on another, everybody’s computer can be my computer.