Tineye is a free tool that helps you conduct reverse image searches. In a reverse image search you're searching for the places where an image has been posted online. In the video embedded below I demonstrate how to conduct a reverse image search.
Applications for Education
Conducting a reverse can be a good way for students to discover information about an object or location featured in a picture. As demonstrated above, when the image is located through Tineye students can click through to the source to see how the image was used and what was written about the image.
Conducting a reverse image search can provide students with a good lesson on digital footprints. Have them conduct a reverse image search for images they have posted online and then count the number of places where that image has appeared.