The Visual Search

Does anybody have familiarity with visual search, especially in regards to Media Asset Management systems?

I just read an interesting article on this technology at webreference.com (http://www.webreference.com/new/010607.html#feature – though I’msure it will be relocated soon!) It talks a bit about general web searches, ecommerce, and stock photography, but not MAM systems.

How tried and true is this technology? Any pointers would be much appreciated!