From their site: With imageloop you can create your own world of photos. Create moving photo albums (called Slideshows) and share them with anyone you like. And the best part: imageloop is completely free. Sign up today and discover the world of imagelooop.
While map mashups are what have defined this genre of application, the second most popular type of web mashup here on ProgrammableWeb are photo mashups. How popular? Just this past week the number of photo-related mashups passed the 500 mark, and there are now 505 listed.