"Most Linux distributions, such as Ubuntu, are capable of installing directly to a USB drive as if it were just another hard drive, but some distributions treat USB flash drives as a slightly special case. DSL, for instance, has an installer specifically for creating a USB-drive installation of the OS. Puppy can also install itself directly to a flash drive through the built-in Universal Installer utility. However, the default options did not work in my case; I had to explicitly use the 'SysLinux' option in its installer menu to make the flash drive bootable.
