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:
 * all pictures in an online album
 * all images tagged with the keyword "sunset"
 * an Amazon.com wishlist
 * a list of houses for sale
 * a list of desktop backgrounds (used by a screensaver)

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)
 * iPhoto from Apple, Inc.
 * Zencast Organizer from Creative
 * Google Photo Screensaver (Windows XP and Vista). Available with Google Pack or Picasa.