I have received an invitiation to try Riya search based on face recognition technology. If you are willing to try Riya, drop a comment here and I'll send you the link.

The Riya image uploader is PC only. Once you upload the pictures, you have to train the software just like you train Microsoft Office for speech recognition.

Here's how a image recognized in Riya looks like (the flickr-like notes appear when you move the mouse over the face)