Here is an interesting use of RSS-- Pheed.com or Syndicated Photography Feeds aims to promote the use of RSS to describe collections of photos.
The Pheed RSs extension adds to the RSS 2.0 spec two custom elements: photo:thumbnail and photo:imgsrc for the URLs of a thumnail image (max dimension 120 pixels) and the image itself. Along with it are Dublin Core extensions for attributes of creator, rights, photo location, format, and subject keywords.
The Pheed.com site aims to provide a search interface to "Pheed" Feeds, for now it looks like a manual process to create as no tools can automatically generate these feeds.
This would be a very cool feature for FotoLog to implement.