I find numbers and statistics very interesting.  I added the Visitors Map to my site last year and I always find it interesting that more and more places show up on it.  It is also a great conversation piece when someone visits my site and sees it.  Tonight, I decided to install Piwik onto my site.  The installation was seamless and the integration was even more seamless.  It does require a MySQL database but for the most part it just uses basic a basic web server that supports PHP.  The really cool thing about this tool is it of course has a WordPress plugin that integrates into my WordPress dashboard. This level of statistics should be interesting to watch over time.

Click on Image to make larger