Another interesting article with security in mind. From the article:
You're probably familiar with the live CD concept -- a fully functional operating system on a CD that can be run on any computer that boots from its optical drive, without affecting the one(s) already installed. In a similar vein, you can set up Linux to run from a USB hard drive drive on any computer that can boot from USB. The live system offers automatic detection and configuration of the display adapter and screen, storage devices, and other peripherals. A bootable USB drive can run a mainstream Linux distribution such as Debian GNU/Linux, and can be secured, personalised, upgraded, and otherwise modified to suit your needs.