The wonderful world of web 2.0 just gets more wonderful, worldly and web 2.0.
SystemOne in Austria, have created Retrievr, which currently appears to be in beta. Another of the ever-growing apps that piggyback off Flickr, it allows you to search for images either by referencing another image, or a sketch that you draw yourself.
So, as an example, you start here:
and then draw a sketch. And as you do, in real time, the search results are updated:
You can then, like me, try to get meta, take an image of the results, sketch that image and see what comes up:
and then try again, with the actual image:
Leaving aside the obvious addictive qualities, and the boon that this should be for designers, what it does show is that image-based/driven searching is getting closer. The general belief is that if an easy way to search images/pictures/video can be found, then a whole new wave of innovation will be unleashed. At the moment, the only real way is tagging (hence the success of Flickr) or social recommendation (hence YouTube, and Google's purchase of it, so it at least gets a foot in the world).
The French, of all people, are trying to develop a search engine which utlises these properties. Called 'Quaero', there's not much information about it publicly yet. Best so far is an Economist article from a few months ago (subscription required), and Wikipedia sums it up quite well.