Take Picitup, for example. The engine offers multiple filtering options, including search by faces, landscapes, products or color preference, while Snap.com gives users a list of choices on the left, with an image preview and characteristic info (like file size) on the right. And Oskope pulls images in from Yahoo, Flickr, Fotolia and others, while allowing searchers to choose whether they want the results presented as grid, stack or on a graph.