retrievr
retrievr simply has to be one of the most inventive, amazing and fun search engines ever! You search in one of two ways, by drawing a sketch online or by uploading a picture. The search engine then looks for other images that match yours most closely.
Now, I know that some of you will say that you can't draw, so you can't use it. Please, just enter a blue blob or a red circle or a green triangle and give it a whirl. It will come up with some amazing images, I promise!