With the release of Firefox 3 Release Candidate 1, all those who have waited long can now download and install it in your system. For Ubuntu users, it is wise to install it via the repository rather than download from the Mozilla site.
To install in Ubuntu Hardy Heron:
Add the following repository to your sources.list
Open your terminal,
gksu gedit /etc/apt/sources.list
Paste the following repositories
deb http://ppa.launchpad.net/mozillateam/ubuntu hardy main
deb-src http://ppa.launchpad.net/mozillateam/ubuntu hardy main
Save and exit.
Perform a update
sudo apt-get update
sudo apt-get upgrade
You should have Firefox 3 RC1 working in your Hardy now.