If you want to distribute USB disks containing the same data to multiple people, then you may find ImageUSB very helpful. This freeware application allows you not only to create USB images, but also allows you write them to multiple USB drives at the same time. This way you can clone a USB disk to multiple USB keys simultaneously.
You can download ImageUSB from the Passmark Software website. The download is as a ZIP archive containing the portable application. Being a fully portable application, it does not require any installation. You can extract the contents of the ZIP archive to a folder and double-click on imageUSB.exe to run it. This application requires administrator privileges because it needs to write to the MBR of the target USB drives.
In order to create an image from the USB drive, select a source USB drive from the list, select Create from UFD option, select a folder where the image file would be placed, and finally click on the Create image button. A progress bar would show the process as it creates the image of the selected USB drive.
If you want to create clones using the USB flash drive image, then you have to select one or more target USB drives from the list, select Write to UFD option, select the USB drive image, and click on the Write to UFD button. This would write the contents of the USB image to all the selected target USB drives that you have selected.
Whether you want to clone a USB flash drive into one clone for personal use, or want to create multiple cloned USB flash drives for software or content distribution, ImageUSB can prove to be very useful. It can write a single USB image to multiple target USB drives at the same time, so number of clones created simultaneously are limited entirely by the number of available USB ports you have in your computer.
You can download ImageUSB from http://osforensics.com/tools/.