There is a channel provided by the upstream provider called FasTrack.

This channel will have RPMS that are going to be included in the normal
update sets (3-4 times per year), but released once a week. These RPMS
will normally be bugfix or enhancement updates and not Security updates.

Accordingly, CentOS has created a fasttrack (note the spelling difference,
it is intentional) repo. This repo will track the upstream FasTrack channel.

If you would like to use the FastTrack repo for CentOS-5, copy the file
CentOS-fasttrack.repo into your /etc/yum.repos.d/ directory and it will
be enabled.

See this upstream mailing list post for more info on fastrack:

Also see the upstream info here: