Let me explain what I am trying to do in detail...
I want to install ubuntu 12.04 (or 12.10) on a 320gb usb drive, and set the boot order to boot usb first. That way, if I want 12.04 to boot, I just have to start my machine with the driver inserted, and if I want to boot windows, I start it with it disconnected.
I have done this on previous computers, but this machine is windows 8 uefi, which I have never done before. I do not have a deep understanding of how uefi works, but I want my main machine to remain completely untouched by ubuntu, and I do not know if this is possible with the new uefi setup.
My machine is a fujitsu lifebook AH532 > 2.3ghz intel i3 > 6gb ram