How can I install Flash in my web browser?

Create a file macromedia-mplug.repo, insert the following into the file and put it under /etc/yum.repos.d.

[macromedia]
name=Macromedia for i386 Linux
baseurl=http://macromedia.rediris.es/rpm/
enabled=1
gpgcheck=1
gpgkey=http://macromedia.mplug.org/FEDORA-GPG-KEY

Run as root, # yum install flash-plugin.

Restart Firefox browser. Done.