Unless I'm way off, Google is already doing a redirection script on all outbound clicks. The endpoint url shows up in the footer of the browser on hover, but if you right-click and copy the link location, you get something like:
That doesn't affect the referrer though. The referrer is still the link where the click came fromo, which woulld still be e.g. google.com/search?q=whatever
The redirect script has been tehre for as long as I remember. It's probably tied in with Google Analytics.
http://www.google.com/url?sa=t&source=web&ct=res&...