Photofeed

A photofeed is a web feed that features image enclosures. They provide an easy, standard way to reference a list of images with title, date and description.
Photofeeds are RSS enclosures of image file formats, similar to podcasts (enclosures of audio file formats).
Feed format.
A photofeed may be in the RSS 2.0 or Atom format.
Image format.
Enclosed images may be in the JPEG, GIF or PNG formats.
Possibilities.
A photofeed can contain:
Photofeed aggregators.
A photofeed aggregator is a piece of software that accepts subscribable RSS 2.0 syndication feeds and downloads or precaches higher resolution images (rather than thumbnails) for later viewing, such as when offline. There are not a tremendous number of photo aggregators yet. (please add)