I can't tell if Savvygraph.com is part of Amazon.com, or if this is a separate company running this. It takes any Amazon.com search terms you enter and charts the results on an X-Y chart showing the Average Rating and the total Number of Ratings.
It's fairly interactive. You can limit the price range using the sliders at the top, and when you hover over any of the pins you get the product image. Clicking on the pin takes you to that item on Amazon.com. Clicking on any of the links on the right limit the search to a smaller subset based on your choice (like a particular brand).
EDIT: I did receive an email from the author who confirmed that the site is totally separate from Amazon.com. Thanks Dave.