My idea is probably absolutely impossible. BUT; my laptop HDD had died on me. I currently have no way at all of accessing a computer, only my tablet and phone. I have a micro USB to USB adapter so I can plug my USB stick into my phone/tablet. Would there be any way of installing Ubuntu on the USB from my phone/tablet? Neither of the devices are rooted either unfortunately.
I think that will not work since the phone has a different configuration rather than a USB driver. I would suggest just sticking to the traditional method of using a USB device or a disc to create an install Windows.