There is a section of the apt-howto reference that deals with keeping a mixed system: http://www.debian.org/doc/manuals/apt-howto/ch-apt-get.en.html#s-default-version though you will end up writing to two different config files inside /etc/apt, so if you aren't cool with that, then try this:
aptitude or apt-get install mozilla-firefox -t testing (or -t unstable) it is true that usually keepign a mixed system is a disaster. however, in the case of firefox, not too many packages have to be upgraded in order to support the latest version - apt-get will handle this for you. i am running a stable sarge with the unstable version of firefox, with no problems. cheers adam black
