New from the Web Developer Juice blog there's a tutorial looking to help you get a memcached server up and running and make it accessible to your PHP applications.
Thinking of implementing caching for your php application , you are at a right place. Just in 10 simple (copy and paste) steps you can install and access Memcached Server.
Their steps use the yum package manager, but several other linux distributions with other packaging systems will probably have similarly-named packages. Since the install process requires loading system libraries and being able to restart the web server, you might needs to have a privileged account to make the installation work. It's a pretty simple process though - install the lib, install memcached, start up the server and test your PHP installation to be sure a sample script can reach it.