Ditto - - Image search that provides easy searching via tags.
Lair - - Unique searchable database of catalogued landscape images, that are available for educational purposes. Several types of search offered all with selectable parameters to narrow your search by location, artist, etc.
Like.com - Visual Search - - Like.com is a true visual search engine, where the contents of photos are used to search and retrieve similar items. Like.com creates a digital signature that describes the photo's contents and enables a more accurate search for similar looking items and products.
PicFindr - - Searches stock image and photograph community sites for images with the ability to tailor the search by usage license type and easy previewing capability.
Picsearch - - Family friendly interface for finding pictures, photographs or animations on the web, available in English, German, Swedish, Danish, and Norwegian.
Riya - - An image search engine that determines similarity of image content through analysis of color, shape and texture.