HOWTO : Upgrade to Firefox 4 on Ubuntu 10.10
Firefox 4 is released recently. It also works on Ubuntu 10.10. You can upgrade it from PPA. Be keep in mind that some of the add-ons are not compatible with Firefox 4 at the moment.
That's all! See you!
sudo add-apt-repository ppa:mozillateam/firefox-stable
sudo apt-get update
sudo apt-get upgrade
That's all! See you!