Installing php-mcrypt on CentOS 6
To install php-mcrypt on CentOS Linux you need to enable a couple extra repos first:
wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
rpm -Uhv epel-release-6-8.noarch.rpm remi-release-6.rpm
Then install php-mcrypt itself:
yum -y install php-mcrypt