Instead of rolling your own look at Piwik. It works very well and is basically a GA clone. I actually like it better than GA in some ways. It's easy to set up a

Instead of rolling your own look at Piwik. It works very well and is basically a GA clone. I actually like it better than GA in some ways. It's easy to set up and you can run it on your own site so you're not contributing to a global tracking fabric.