Link Tracking with Ajax

I found this rather interesting:

One of the more interesting aspects of Ajax is the ability to track a user’s interaction within the browser. I wanted to investigate navigation patterns, so I have written an Ajax based link tracker. If you press the “Ctrl??? and “X” keys you will be presented with an overlay which displays links usage by percentage. This functionality was created with JavaScript and a very simple API.

Very inventive use of Ajax.
[tags]ajax,web2.0,web 2.0[/tags]