Universal USB Installer

Easily install your favorite Linux operating system on a flash drive or USB key no larger than your thumb (Thumb Drive). Your Portable Linux operating system can then be taken with you, and run from any computer that can boot from the USB flash device. Bring your operating system, applications, files, email, bookmarked favorites, games and more with you. It's your very own portable operating system you can carry in your pocket.

http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/