Did you choose to install openoffice later to save some time with Fedora OS installation? Now, instead of downloading openoffice or any other packages from internet we can point our yum repo file to use repository from the Fedora DVD ISO file or from the USB if you have the image file on USB. Let's assume the ISO file is on USB:

First, loop mount the ISO file to a temp directory

• mkdir /opt/temp
• mount -r -o loop /media/Fedora/Fedora-12-i386-DVD.iso   /opt/temp  (your path to ISO image will be different, wherever is the ISO give the absolute path to it after 'loop')

Lets go to /etc/yum.repos.d

•  cd /etc/yum.repos.d

Create a 'old_repfiles' directory and move all files into it from /etc/yum.repos.d

• mkdir   old_repfiles 
• mv   *  old_repfiles/

Note: We moved all the files from /etc/yum.repos.d to /etc/yum.repos.d/old_repfiles, we're gonna leave them untouched and restore them once we're done so that system is back to its normal settings.

Create a file named 'fedora.repo' in /etc/yum.repos.d

• vim fedora.repo

Copy and Paste the following into the fedora.repo file

•  [fedora]
  name=Fedora $releasever - $basearch
  failovermethod=priority
  baseurl=file:///opt/temp/
  enabled=1
  metadata_expire=7d
  gpgcheck=1
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$basearch

Save and Exit by typing

• :wq

Now, install whatever you wanted to, in this case openoffice, lets try the writer

• yum install openoffice.org-writer 

Now, once you're done

• delete the fedora.repo file that you created from /etc/yum.repos.d
• And you gotta restore all the repository files we moved into /etc/yum.repos.d/old_repfiles back to /etc/yum.repos.d

Becareful with the 'mv' command, you might loose data.