Just discovered something quite amusing. Go to google, and deliberately search for a website that you know has Google Ad-words embedded in it. When you get to that site's "result", click on the link to view the cached version. Look at the Google Ad-words.
(how to find a site like this? search for *.blogspot.com and any result whose snippet begins with blog*spot has ad-words. or just search for justinw.blogspot.com)
I guess not surprising. Google folks think of everything, or at least their superhuman linux cluster-brain does.