[ Thanks to linuxaria for this link.
“In this article we’ll see 3 way of installing Ubuntu on a USB
drive. We’ll see how to create a live USB Ubuntu disk, just like
your live CD. Only difference is that we’ll be booting and
installing Ubuntu using this live USB diskette, and as last option
how to do a full installation of ubuntu on your USB drive.
“Author: Joshua Bulman
“Option 1: Boot Ubuntu as a Live CD from a USB Flash Drive
“Use this option to install Ubuntu as a Live Install, which
allows you to boot from the USB flash drive in Ubuntu, experience
the Linux environment but will not retain any changes or settings
after you shut down. This is a great way to get a feel for the OS,
test some of it’s capabilities as well as typical hardware