Windows 7 Tip: 
Ubuntu Live USB Imager is new app which allows you to create an Ubuntu Live USB device from a Windows PC. Now you don’t have to be using Ubuntu to make an Ubuntu Live USB. In addition to being able to create an Ubuntu Live USB, the program can make Live USBs for other Ubuntu variants. Creating Live USBs for Kubuntu and Xubuntu has been tested successfully, and it is very likely that other variants (Edubuntu, et al.) can be installed as a Live USB as well.
Read Also: How to Install Ubuntu in Windows With Wubi
Read Also: Install MSN Messenger on Ubuntu Linux
An Ubuntu Live USB device allows you to take the Ubuntu Linux operating system with you anywhere! In addition, if you ever run into a problem where you cannot boot Windows (and cannot access your files), you can use an Ubuntu Live USB drive to boot your computer into a nice Linux GUI environment and recover your files. An entire operating system in a thumb-drive. Pretty cool, huh?
The application is fairly simple. First, you select an ISO image or CD/DVD source. Next, you choose the thumb-drive that you want to install the ISO / CD / DVD image on. Finally, you can select the size of a persistence file (this stores your documents and settings on the USB drive even after you have shut-down the computer – highly recommended). There are various persistence file sizes from 128MB to 4096MB so that you can maximize the use of your thumb-drive capacity.
Does the same tool act same for Windows XP and Windows 7 ?????
very Nice Post.
According to the tests I performed, this software works the same on all versions of Windows NT at version 5.0 or higher (that covers 2000, XP, Vista, and 7).