Visual search engines have been around for a while, and as such is always being touted as the next big thing. One search engine that does a really great job is Like.com. Although its primarly for brand/style based shopping, it does a reasonably effective job at finding things you search for. I’m surprised it does not get more press, but maybe I run in the wrong circles. I would love to know the algorithm(s) they are using for this. Its pretty clever what you can put together these days.