Sketch something in the white box, and Retrievr will do its best to find Flickr pictures of what you drew. My results were a bit mixed, as you can see in the screenshot to the left (click for a larger version). With my amazing art skills, I drew a picture-perfect (ha) rendition of a tree. The site did its thing – lo and behold, the first result is a picture of a tree! Unfortunately, nowhere near all of the results are trees. But there are a couple, and some of the rest are sort of vaguely tree-looking. I got similarly apt results when attempting to draw a santa hat.
Obviously, the service has a while to go yet. But I’m excited! I experimented with examples of similar retrieval methods in grad school, but none were as effective as I’ve found Retrievr to be. Sometimes finding images with keywords just doesn’t cut it – this sort of graphical search has a lot of potential.