I am using ubuntu ( 13.10 ) on a flash-drive. I can move that flash drive all the time and can use it almost in every computer. but to do that, first I have to go to BIOS settings of the computer and make my flash driver priority first. but for example that imagine a computer that is turned off. I am connecting my flashdriver and opening the computer, and computer will start from my flash driver automatically. without changing the BIOS setting of computer. so my Flashdriver must show itself as the first priority driver and so on, computer will start by ubuntu automatically.
just don't misunderstand me, this flashdriver is not a persistant stffs... I have installed ubuntu to my flashdriver like how you do it for a normal hard-driver. so it is acting like a hard-driver all the time- just a little bit slower :) .
I hope I could explain myself, my English is not really good :) .