Today I found this useful piece of info and I wanted to share it with ppl…..
Here is Firefox 4 stable repository for linux users:
sudo add-apt-repository ppa:mozillateam/firefox-stable
sudo apt-get update && sudo apt-get install firefox
Or if that doesn’t work for you just visit Mozilla website http://www.mozilla.com/en-US/firefox/new/ and download and install 🙂