Has anyone been playing around with Robot Replay? It is a analytics program created by an AJAX developing company that tracks the mouse of your visitors. About two months ago I was talking to my brother about playing with some programming to create something like this as it could be very helpful to actually watch exactly what your visitors are doing. It records each session and then lets you play it back through their back end and it shows you the session of that visitor. When they scroll down, how much text do they read, what they click on and when they click it.
It is pretty cool I haven't tested it on enough sites yet, but I have used it to make some tweaks to some content placement and ads on a few sites. I'm running some tests on some affiliate and Adsense type pages to see if it will help with placement to enhance click throughs and conversions.