There's a interesting site from Sweden called 'Polar Rose' that has gotten a few peoples attention over the last couple of days. The company is creating a technology that uses a combination of computer face recognition algorithms and user feedback to identify and tag people in pictures.
The technology is a way of giving context to visual content that is hard for search engines to process. Currently search engines like Google have to index pictures based on tags that are attached to them or the content of the text around the images.
The company is creating a plug-in for the Firefox and Internet Explorer browser that finds people in photographs. When the software finds a person in a photograph that the user is viewing, it displays an icon on the person and requests the user to identifies them if they can.
Google prototyped a somewhat similar technology (minus the face recognition algorithms) called the 'Image Labeler' a few months back. Check out this article for more information.