"Nobody writes much about the Debian Live Project, which went
from a bunch of stable images for Intel architectures to offering
stable and testing images not just for i386 and amd64 but also for
PowerPC, the latter in a time when many distributions (Fedora,
Ubuntu) have abandoned the Power architecture almost entirely.
"Users of i386 and amd64 can also choose from monthly, weekly
and daily builds of Debian Live with GNOME, KDE, Xfce, LXDE or the
standard install, and there's also a Web-based utility to build a
custom Lenny, Squeeze or Sid image.
"Aside from the usual ISO images, there are also .img files for
USB drives (don't ask me exactly how to make us of them, because I
haven't yet figured that out). There is a manual for Debian Live.
It's pretty geeky, but I have a feeling I'll be able to drop a
live, bootable image on a USB flash drive without taking the
interim step of burning an ISO to a DVD-RW and using it to install
Debian Live to the flash drive, which is the way I've been doing it