Get it? Goldn Retrievr = . . . Golden Retriever! Fetch, boy, fetch! Good boy! Good dog! Goo -- ah, forget it.
There's a new, very interesting app out called retrievr. As the picture above might indicate, it allows you to draw a doodle and then it searches through some subset of flickr and attempts to find photos with similar shapes and colors.
Really, it usually does a better job of it than my example would indicate, but I haven't had a lot of time to work with it, and the program's acting a bit sluggish tonight. A lot of big sites are linking to it, and the server's getting hammered. Some times I could only get a "Too many open threads" error message. This guy had better luck.
This isn't of course the only example of its kind -- there's obviously much ongoing (classified or secretive-corporate, for the most part) research on facial-recognition software. Princeton University has the Shape Retrieval and Analysis program that searches specialized datasets for 2-D or 3-D objects that match sketched-in input.
imgSeek (from which, I gather, Retrievr was derived) is an open-source photo manager and searcher that you can install on your own computer. Like most open-source projects, though, it's in a constant state of geekflux, so unless you're prepared to figure out frequent riddles like
# When starting imgSeek, all I get is: "Warning: Unable to load the C++ extension "imgdb.so" module. Make sure ...
# I get an error when exiting: Fatal Python error: PyEval_RestoreThread: NULL tstate
# The metadata editor ignores or refuses to save comments with extended characters on my locale.
it probably won't be for you.