First, it is no longer neccessary to burn CDs in order to install Ubuntu (as any other Linux flavor i assume).
If one has a running Ubuntu install present, it is very easy:
- download the desired distribution (e.g. the Xubuntu 64-bit Desktop release to your harddrive
sudo aptitude install usb-creator
- plug in a USB-disk with 1GB capacity at least
- open Menu – System – USB Startup Disk Creator and
- follow the menu instructions.
Doing this you end up with a desktop realease of Xubuntu on a USB-disk. You can boot and try out Xubuntu from the disk without changing anything on the host-computer. Or: you can start the installer to have the operating system permanently on harddisk.
But: if you might want to have an alternate installation USB-disk you have to undergo a more difficult task.
Why would you do this? The alternate install offers more flexibility concerning crypted partitions or installing just a command line “barebone” version of ubuntu. I started this task since the fluxbox is my favorite desktop manager and I wanted to play around a bit with creating my own Ubuntu flavour…