Gazopa provides image upload and drawing interfaces for image search. The idea of finding similar images by comparing against a submitted image or drawing is not new, but search tools that use this tech have failed to catch on in consumer sites. People with information retrieval background might be familiar with IBM's QBIC, query by image content, technology for instance.
Gazopa looks very interesting, and the results are not bad at all, even with my crude bicycle drawing above. The Flash drawing tool is a little rough around the edges, but I'm sure that will improve as well. Looks like one of the best attempts to bring this to the masses so far.