I have total 5 USB that i use for different purposes. In 4 USB i have stored by blogs important files and data, and 1 is for normal use. Like copying movies, songs, documents etc..
Some time i need to clone my USB drives (to backup its data) and for that i use a very useful free software called ImageUSB. Let me give you a short overview of this cool application, that can help you in creating image of your USB drives.
ImageUSB application helps in mass duplication of USB Flash Drives to create image of all USB drives. It is a free tool available for windows user which allows you preserver all slack and unused space during the cloning process. It also includes master boot record also known as MBR.
If you want to backup up or duplicate the data of one USB in another one, then this tool can do this very easily. The process provided by ImagUSB is simple and you need to just insert all the USBs in the ports and ImagUSB tool will create image in all the USBs in a few minutes.
Try it and you will surely like it.