Anyone who uses Google’s products or services, such as gmail, gtalk, google searches, etc should read this article at Ars. It discusses how you can access your dashboard to see what information Google keeps on you, and you can opt out of various parts as needed.
As someone who reluctantly uses Google (my account on gmail is called “reluctantkirk” – doesn’t get more obvious than that) and who tries to keep my privacy intact as much as possible, I was a little disconcerted to see that I could go back and see an eternal history of Google searches and that somehow several friends have ended up as Google contacts when I didn’t intend them to (I don’t want to share their info with Google if it can be avoided).
That being said, the dashboard allows you to manage these things, delete history, remove contacts, etc. Thank you Google for trying to make money without doing evil.