I switched to the dvorak keyboard layout about a year ago. I now use dvorak full-time at work and at home.
Recently, I went on vacation to Peru and found myself in quite a conundrum. Internet cafes were qwerty-only (and Spanish qwerty, at that). I was stuck with a hunt-and-peck routine that grew old fairly quickly.
That said, is it possible to be "fluent" in both qwerty and dvorak at the same time? If not, are there any good solutions to the situation I found myself in?
For your situation of being at a public computer that you cannot switch the keyboard layout on, you can go to this website: http://www.dvzine.org/type/DVconverter.html
Use this to translate your typing and then use copy paste. I found this very useful when I was out of the country and had to write a bunch of emails at public computers.
Put this Dvorak Utility on your USB drive.
Run this app and it will put a icon in the system tray on windows. This icon will switch the computer between the two keyboard layouts and it works. (If you have tried switching back and forth from dvorak to qwerty you will know what I mean. Windows does the worst job of this one bit of functionality.)