When I was in the process of setting up my new VPS, I decided I would try out mod_pagespeed (conveniently it had just come out of beta a few days earlier). It turns out, it's very easy to set up and very easy to use.
First of all, you need to download the correct package at:
Once you have downloaded it, its as simple as running:
dpkg -i mod-pagespeed-*.deb apt-get -f install Or for CentOS you run yum install at # if you do not already have 'at' installed rpm -U mod-pagespeed-*.rpm
The default install includes things such as the minification of CSS and js files and also the combining of CSS files (js can be enabled too). Inline images, CSS, and js is also enabled by default, which allows these types of files to be included in the main HTML layout if they are small enough to justify doing so. This will save requests to the server for more files.
As well as the defaults, i decided to enable a few none default options in the config file:
Some are not 100% ready for production but the risk value of them is quite low.
From initial tests, it seems to have reduced the page load by about 1/3. Which on a small site may not be a lot, but on a big site with a lot of images etc, this could be a huge saving in bandwidth costs, and also a lot nicer experience for the user.