Today saw the release of the release candidate (read beta) of MandrakeMove, a version of Mandrake 9.2 that boots off a CD but doesn't actually install onto the hard drive.  Nothing new there - Knoppix (KDE) and Gnoppix (Gnome) editions among others have done this for some time, but what's different is that this is the first to utilize USB storage keys and allow for the CD to be ejected so other CDs can be used - like to burn a CD, or read another.

For more information and some screenshots, see the press release.