OK.  So you’re running something that requires php above 5.1.x and you need to update your PHP instance.  The problem is, Centos 5.x doesn’t make it easy.

So here’s the quick and simple solution.

create the following file in yum.repos.d:         CentOS-Testing.repo

inside that file, just paste the following:

[c5-testing] name=CentOS-5 Testing
baseurl=http://dev.centos.org/centos/$releasever/testing/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://dev.centos.org/centos/RPM-GPG-KEY-CentOS-testing
priority=5

Now, just save the file.

as root, issue the following command:

yum –disablerepo=* –enablerepo=c5-testing update php*

EDIT:  That’s 2 dashes before disablerepo and enablerepo!!!

That should do it!  You’ll now have updated your php and it’s components to php-5.2.x

Hope that helps!