There are two ways to install Firefox 4.0 Beta7 In Fedora using a repository.
There is a Remi repository and a Spot repository.
In my opinion The Spot option is your best choice, and Remi the easiest, since all you have to do to set up the Remi repository is to install a remi-release-rpm matching the Fedora version you use; Fedora 12 users should opt for Remi since Spot only has repo’s available for Fedora 14 and -13.
The Spot version of Firefox is smoother and the opening and closing of tabs look better (animated).
For the spot repository do as normal user in your terminal (fedora 13 and 14 only!)
Then as root:
mv fedora-firefox4.repo /etc/yum.repos.d/
yum install firefox4
Installing Firefox from the Remi repo is after installing the remi-release-rpm also yum install firefox4.
To my surprise wget is not in the default Fedora 14 installation, so if you choose for the Spot repo option first as root:
yum install wget