http://www.fedora.us/wiki/FedoraHOWTO
Please follow the directions on this page if you do not already use Fedora Extras. Report problems of firefox & thunderbird to bugzilla.fedora.us.
http://togami.com/~warren/archive/2004/foxbird.sh
FC1 users can also use firefox & thunderbird from the Fedora Extras stable repository, but unfortunately the Preferred Applications framework in FC1 is a bit broken. As a workaround you can run this script as your non-root user to set your profile to use these two applications.
Warren Togami wtogami@xxxxxxxxxx