The Ubuntu Netbook Edition (UNE) Live CD is a version Ubuntu designed for use on Netbook PCs with up to 10 inch screens and at least 256MB RAM. It can operate like a Live CD or install Ubuntu on your Netbook. You can also use USB Live Startup Creator to create a USB Netbook Live drive to use instead of the Live CD disc. The Ubuntu Netbook iso image (.iso) is available from http://www.ubuntu.com/netbook/get-ubuntu/download. You also can download it from http://releases.ubuntu.com/maverick/ as ubuntu-10.10-netbook-i386.iso. You can even burn the image file on Windows. Use the usb-creator.exe program include on the ISO image (accessible once you burn the CD or mount the ISO image with a virtual drive).
Ubuntu Live USB drive
With the USB Startup Disk Creator utility, you can install any Ubuntu disc image on a USB drive. The USB Live/install drive is generated using the CD iso images that you first have to download. The USB Startup Disk Creator is installed by default (System | Administration | Startup Disk Creator).
The Make Startup Disk window opens with an entry at the top to select an ISO image, and an entry below to select the USB drive to use. Click the Other button to locate a specific disk image to use. Then click the “Make Startup Disk” button to install the ISO on the USB drive.
The “Make Startup Disk” operation will not erase any data already on your USB drive. You can still access it, even Windows data. The Ubuntu Live OS will coexist with your current data, occupying available free space.
To boot from the Live USB, be sure your computer (BIOS) is configured to boot from the USB drive. The Live USB drive will then start up just like the Live CD, displaying the install screen with options to try Ubuntu or directly install.
When you create the Live USB drive, you have the option to specify writable memory. This will allow you to save files to your USB drive as part of the Ubuntu Live operating system. You can save files to your Document or Pictures directory and then access them later. You can also create new users, and give those users administrative permission, just as you would on a normally installed OS. With the Login Screen tool you could even have the new user be the automatic login, instead of the ubuntu user. In effect, the Ubuntu Live USB drive becomes a portable Ubuntu OS. Even with these changes, the Ubuntu Live USB remains the equivalent of a Live CD, just one that you can write to. There is no GRUB boot loader. You still use the install start up screen. In addition, you cannot update the kernel. One advantage of this approach is that your other data can coexist on the USB drive, accessible by other operating systems.
If you want a truly portable Ubuntu OS, just perform a standard installation to a USB drive, instead of to a hard drive. You will have to create a new clean partition on the USB drive to install to. You would either reduce the size of the current partition, preserving data or simply delete it, opening up the entire drive for use by the new Ubuntu OS.