Install Ubuntu form usb flash drive

Ubuntu is one of the best OS which is based on Linux kernel , In this tutorial we are going to learn how to install Ubuntu from USB drive. This procedure is very handy for portable notebooks etc.., which do no have CD/DVD drive and it will be also useful when your CD/DVD dive has been malfunctioned.
I just don't want to be too long, so lets get straight to the work ;)
Requriments:

• A small application called UNetbootin which you can download from here.
• USB drive.
• Ubuntu ISO, if you dont have ubuntu iso download one from here. 
• plug-in your USB drive and make a back up of it because your drive will be formatted in this procedure. 
• Launch UNetbootin by double clicking it. 
• Now select "Diskimage" and browse to the ubuntu iso and select it.
• Make sure that the "Type" is selected as "USB drive" and also make sure that the drive letter belongs to your USB drive.
• Now click "OK" and pay some patience till the procedure is completed.

Once the procedure is completed click "EXIT", from now you can install or enjoy live cd right from your USB drive.