USB Linux installation enables you to install a portable Linux operating system on a flash drive or USB key no larger than your thumb. This portable Linux operating system can then be run from any computer that can boot from a flash device, allowing you to bring your operating system, desktop, applications, files, email, personal settings, favorites, games and more with you. It’s like having your own personal operating system you can carry in your pocket. On this site, we provide many simplified portable Linux flash drive installation tutorials.
Information from pendrivelinux.com