Google Image Swirl [googlelabs.com] is an experimental feature in Google Labs which is based on new computer vision research to cluster similar images into representative groups in a visual, exploratory interface.
For example, for an "apple" query, images of the fruit appears next to many products or logos of Macintosh. Users can then click on any thumbnail and a cluster of images will "swirl" into view. Other examples include keywords like car or Eiffel tower.
Via The Official Google Blog and Thnkx Andrew!