Create ubuntu bootable USB key from your windows machine using LiLi USB Creator
LiLi USB Creator is a free software for Windows that allows you to create a bootable Live USB key with a Linux on it.
This software also offers an exclusive option of automatic virtualization to directly run Linux in Windows without any configuration nor installation.
LiLi USB Creator Features
* create bootable Live USB of Ubuntu, Fedora, Debian, Damn Small Linux, Puppy Linux and many others !
* enable persistency of your data
* launch Linux directly in Windows with a special Portable VirtualBox
* hide created files on the key
Download LiLi USB Creator from here
http://unetbootin.sourceforge.net/ is good for liveCD.
Persistency of your data that is cool!