Here are some very useful plugins as extensions for Yum:

* Fastestmirror, this plugin works to sort mirror of the repository based on connection speed so that yum is expected to be faster in the download package.
* Priorities, this plugin works for the repository to determine the priority of other repositories so that a package from a repository will not be crushed package from another repository.
* Protectbase, this plugin works like a plugin but more simple priorities, in order just to protect packages from a repository is not affected by another repository.
* Refresh-updatesd, this plugin works for yum-refresh through DBus if updatesd detected when using yum update through the CLI.
* Versionlock, this plugin function to lock a version of RPM to RPM is not updated to the newer version.
* Downloadonly, this plugin works for RPM-only download RPMs using yum without having to install these RPM.

List of yum plugins can be found at http://wiki.linux.duke.edu/YumPlugins or by using the command:

admin@smartproteam~$ Yum-yum list *