Woopra is an application for tracking website access. It involves both a webserver and local client applications. The client interface is really spectacular.
First off, it is in beta release. I had to wait several weeks to get my website approved. I have since applied for two additional websites and am awaiting approval on them. So I don’t know how long you will have to wait to use this.
First you sign up on their website and when you are approved you get a unique identifier so that woopra can identify your site’s pages. Then you add some code to your web pages (4 lines of javascript) that includes the identifier and will make a call to woopra every time the page is visited so that it can gather statistics. There are also plugins for WordPress blogs and vBulletin (with probably a lot more to come).
Then you download a client application for your OS (Windows, MacOS, Linux) and then the fun begins. I should mention that the installation on Windows was very easy but getting the right version of Java on the Mac was a bit of a pain in the rear (the application uses the very latest version of Java).
The client shows a myriad of statistics in a very graphical way (often with choices of the type of graph). It even includes a live view of who is on your site at the time you are observing. Here is just one screen from the client:

You can also set notifications for specific actions so that you can be alerted when they take place. It is very impressive.