Knoppix is an excellent distro. Great automatic hardware detection, nice auto setup, KDE, lots of built-in packages/apps (openoffice, calculators, editors, games, browsers, and more). Plus, the functionality of Debian is included.
It's so good that you might choose it as your primary distro.
To copy it to the hard drive, open a shell prompt, type in sudo knoppix-installer, and press enter. VOILA! Asks you a short series of questions, and finishes. Shut down, take the CD out, restart, and you've got a Debian installation.
I would highly recommend it to anybody.
Download it from http://www.knopper.net/knoppix/index-en.html
PS: DO NOT USE knx-install! It's no longer being updated. Use sudo knoppix-installer instead.