Gnoppix is comparable with Knoppix but comes with Gnome [1]. Morphix is a modular distribution, with live-cd support and runs without any configuration (you burn the CD, you put it in your CD-ROM drive, you boot and it works) [2]. More CD-ROM based distros on kefk.net [3].
[1] http://www.ao.kernel.org/pub/gnoppix/ Version 0.4_2 (beta)
[2] http://morphix.sourceforge.net
[3] http://www.kefk.net/Linux/Distributionen/CD-basiert/
