Google introduces search by image. Basically this is a reverse lookup for images. Don’t know an image’s source? Find out using search by image. This is basically tineye, but powered by Google, which should make it much more robust.
"It’s been hard work, but we rebuilt our site from the ground up. Our goal is to turn Cheerios.com into a community-fueled project that aims to provide reliable answers to questions about Cheerios. Along the way, we want to hear stories from real people like you."