I am trying to use Google Search by Image, which was apparently implemented in July. Here are the instructions
You are supposed to be able to drag an image from your computer onto the search box at images.google.com to search by image. When I drag and drop, the browser just loads the image (such as file:///C:/Documents%20and%20Settings/Home/Desktop/some_pic.jpg).
Firefox 5.01; Windows XP SP3