Bloglines staff not only created a popular feed reader, in fact the most popular web RSS aggregator, but also figured out how to play with the zillions of feed images they index every second. They created the Bloglines Image Wall.
Bloglines announced that as they index zillions of pages every hour, they index feed images too. The Bloglines Image Wall picks up these images as they come in and places them into a constantly updated grid. In an autoupdating grid, you can spot the current blogosphere images flash right in front of you. Each image is clickable, taking you to its source blog or feed in Bloglines with a handy subscribe link at the top if you like what you see.
Since the Image Wall is comprised of dynamically generated images from user feeds, it may contain language, content, images, and themes of an adult or controversial nature and they make you agree to some terms before you proceed.
This is an interesting application of the use of images in feeds. Full text feeds have a better chance to get the image included in such tools. I am sure many new tools will be developed soon enough which harness the images you post on your feed.