There are many of these live cd and compact Linuxes.
There's another one called Puppy Linux which you can google.
A check of articles by Marcel Gagne from a couple months ago
in Linux Journal gives more install info.
the latest wrinkle in these things is the Live Cd which can be
updated and personalized.
So you load the Live cd, set up your stuff and can then take your
'desktop' to any other machine such as net cafes and whatnot.
At the end of the session I guess you can request a cd burn of
that new info, k3b (the disc burning program in Linux) runs and
voila-- personalized live cd.
The operating system bootable from a flashdrive is a notion that
has been around for a while and used in a hardware build from
Linux Journal a couple months back.
I'm fascinated by the idea of using the flashdrive on a thin client
and having some sort of ATA over ethernet set up in a home network.
But for me, the whole Linux thing has been slow going and there
are many reasons why it's not ready for prime time.