Comment Re:Refreshing (Score 3, Informative) 133
And I should point out (since the GP doesn't know about referers, he probably needs more than a one word answer) that the Referer is a field in your HTTP request that's automatically sent by your browser telling it the address of the website that you came from. Since Google (and other search engines) put the query string in the URL of the search results page (like they should), the website can read the results out of the URL and know what your search terms were.
Google didn't invent this as a way to invade your privacy -- it's been a feature of the web since the early days.