I've used Linux in just about every way possible and for nearly every use case. I love how flexible the open source operating system is because it removes most limitations found on other OSes. One way I've used Linux is directly from a USB drive. Not only is this the easiest way to install Linux, but it's also a viable way to use Linux. With a tool like uNetBootin, you can burn an ISO to a USB drive such that it's possible to boot to Linux, bypassing the installed OS...
