You can hang it on your key ring
Create a Bootable USB Flash Drive for Multiple Operating Systems: Simple Step-by-Step Guide
If you work in IT or provide your own IT services, you probably install and reinstall operating systems for clients quite often. Traditionally, OS installations have been implemented directly from an OS installation disk, but because disks are so easily scratched or damaged, most people in IT use USB drives. This is a more effective method, but it still has one drawback, similar to using disks.
USB drives are generally more reliable and efficient than disk drives, but like disk drives, most USB drives are single-purpose. Because each client can have a different preference for an operating system, you may need to deploy different operating systems at random times. For example, one client may want a clean install of Windows 7 Ultimate, and another client may want you to install Ubuntu for them.
Typically, this means you’ll need multiple USB drives. For example, you might have a Windows 7 boot drive, an Ubuntu boot drive, a CentOS boot drive, and so on. If you want to keep the number of drives down, you can consolidate your bootable operating systems onto a single USB drive that you can use to deploy multiple, different operating systems.
