Google will get the data if it wants. Do you think that sharing that with us webapp creators makes it worse? Also, I don't necessarily want it to be only from Google... just want a solid tool that you can rely on. Google is the only company that came to mind when I thought who can deliver that.

No doubt. As I mentioned, in all probability, Google already does it. And sharing it with webapp creators does not make it worse. Heh.. I used to create web applications and am a developer for a MORPG.

Google kind of does this already - when you click on search results, it's not just a hyperlink, it fires an event onMouseDown to tell Google which results you're clicking on.