:: how to installing firefox 4 on debian

# wget //mozilla.ftp.halifax.rwth-aachen.de/mozilla/firefox/releases/4.0.1/linux-i686/en-US/firefox-4.0.1.tar.bz2

or you can download firefox 4 on this

:: installing firefox 4 from source

# tar -xjf firefox-4.0.1.tar.bz2 -C /opt/

:: create shortcut for firefox

0. right-click gnome panel and select Add to Panel..
1. select Custom Application Launcher..
2. add value on Add Louncher, like:
Type: Aplication
Name: Firefox
Command: /opt/firefox/firefox
3. click OK button

:: links
+ google