Face recognition http://www.face-rec.org/general-info/ and fingerprint-based identification http://www.cse.msu.edu/biometrics/fingerprint.html have become popular researches in computer vision which has been successfully implemented in many applications. Recently I read from the ACM TechNews, Friday, October 15, 2010 an article about a new technology to identify people by their ears.
Biometrics researchers at the University of Southampton have developed a new technique called the image ray transform that can highlight tubular structures such as ears. In the article Professor Nixon, one of the UK’s earliest researchers in this field said that “ears have certain advantages over the more established biometrics as they have a rich and stable structure that is preserved from birth to old age and instead of ageing they just get bigger. The ear also does not suffer from changes in facial expression and is fixed in the middle of the side of the head against a predictable background, unlike face recognition which usually requires the face to be captured against a controlled background.”
For the detail article you may visit http://www.ecs.soton.ac.uk/about/news/3438
You can download the paper at http://eprints.ecs.soton.ac.uk/21546/. This paper just presented in the IEEE Fourth International Conference on Biometrics.