This post made me realise that installing the pre-built firefox binary isn't as straight-forward as one might like. A small nuisance is that the getfirefox.com versoin is only 32 bit, but that's life.
Here we go.
Download the standard binary version of firefox from here:
You can install it wherever you want, but I'm going for a local installation. Put the firefox-19.0.tar.bz2 in your home folder and untar it:
tar xvf firefox-19.0.tar.bz2 cd ~/firefox/ ./firefox
If you get
bash: ./firefox: No such file or directory
then you are missing 32 bit compatibility libraries:
sudo dpkg --add-architecture i386 sudo apt-get update sudo apt-get install ia32-libs sudo apt-get install xulrunner-10.0:i386
To get flash set up you'll need the 32 bit version. Download the 32 bit version from http://get.adobe.com/flashplayer/?no_redirect
mkdir ~/.mozilla/plugins -p mv ~/Downloads/install_flash_player_11_linux.i386.tar.gz ~/firefox cd ~/firefox/ tar xvf install_flash_player_11_linux.i386.tar.gz cp libflashplayer.so ~/.mozilla/plugins/libflashplayer.so
And that should leave you with a working firefox versions. Note that running 'firefox' as a command will invoke iceweasel if installed. To get around that you can e.g. do
echo "alias ffox='$HOME/firefox/./firefox'" >> ~/.bashrc source ~/.bashrc
after which you can launch firefox by running ffox form the terminal. A standard installation would be to put everything in /opt and set up a .desktop file -- but there's plenty of guides to how to do that.