retrievr

RETRIEVR is an experimental service which lets you search and explore in a selection of images by drawing a rough sketch. One thing to keep in mind is that retrievr doesn't do object/face/text recognition of any kind, so if you're drawing an outline sketch of a chair, it almost certainly won't get you one back (except your index only contains images of chairs). Another thing to know is that there's currently no way to specify the aspect ratio, so you have to rescale the image in your head (things that are close to the borders of the image you're thinking of should be close to the borders of your sketches), but that's really more of a missing feature of the drawing flashlet than an inherent problem. Sometimes it also helps to remove detail instead of adding it. Personally, I see retrievr more as an "exploration" tool than as a "search" tool, and it seems to work very well for that.
Link to the website :
http://labs.systemone.at/retrievr