Rumble on the Web: Google Calls Out Bing on the Google Blog
First they associated some random gibberish searches (e.g. "hiybbprqag") with some real, and very unrelated websites in their own search engine (e.g. searching hiybbprqag returned a result for The Wiltern Theatre). The search query was something that no user would ever type into Google, and the result made absolutely no sense.
Let the fun begin.
Armed with the Bing toolbar, the Googlers used Google to search for the fake searches, logging some traffic on these fake queries. Low and behold, after some time, the same term could be searched on Bing... yielding the same result. Now why would Bing associate those two things if: (1) the Googlers never once searched Bing for that term, and more importantly (2) the search term and the result had absolutely nothing to do with one another?
Curiouser and curiouser.
Check out the whole article (including screen shots) over at the Official Google Blog. It makes for a fun read.
Kinda makes you wonder about how search engines and —especially toolbars— really work (and as an aside, what they're learning/ capturing while you work).