Every once in a while you get a link to a site that you have to send around, or blog in my particular case. The application is called Retrievr and by its unique spelling it is obvious that it is related to Flickr. What is not so obvious is how addictive this application is once you get a handle on it.
In a nutshell, it provides a unique search interface for a subset of flickr photos. By sketching out a drawing using a Flash based widget embedded in the page, the application makes calls to an algorithm that matches your drawing, colors and all, to photos retrieved from the Flickr database. It makes use of AJAX to incrementally make calls to the service so that as you are drawing your sketch you can see your results updated in real time.
I love to see applications like this that take advantage of numerous ‘Web 2.0’ technologies and ideas to subtly combine them in this way (I could write an entire post on how many indiscriminate uses of tags I have seen in the past few months.) The site and interface is clean, and it just works how you would expect. No fluff, just a great application that is a lot of fun to play with.