"Linux has long made life easy for tire-kickers. The latest
version of Ubuntu, however, makes it simpler than ever before to
take Linux for a realistic test drive--without risking a single
byte of data on an existing Windows system.
"Most Linux distros today will run as so-called Live CDs, which
install and run without loading anything permanently onto a host
system. A Live CD is a great way to get a quick look at a new
distro or to test its hardware support, but it is really too
ephemeral to use in a realistic, day-to-day desktop environment.
Since a fully functional Linux installation, however, requires its
own disk partition and file system, this is a step many Windows
users are reluctant to take..."