Dag Wiers provides an excellent repository for Red Hat flavored Linux systems. Adding them to CentOS 5 is easy.
First download the “rpmforge-release”-rpm. For CentOS 5, I choosed rpmforge-release-0.3.6-1.el5.rf.x86_64.rpm. The rpm’s are available at http://dag.wieers.com/rpm/packages/rpmforge-release/. Then install the rpm.
rpm -ivh rpmforge-release-0.3.6-1.el5.rf.x86_64.rpm