Multimedia Collages

Newsbound
Visual-storytelling platform that can combine photos, graphics, animations and text into a slideshow. Considered part of explainer journalism, the company behind the site can be hired to create pieces.  

Storify*
Social media aggregate. Publish elements - photos, tweets, videos together. Free.

Story Planet
mix videos, photos texts and graphs with timelines, etc.

Tumblr*
This social platform allows users to see posts from all of the blogs they follow in a single stream. Sort of Twitter, but with full text and more images. You can populate your stream with content by others simply by clicking the "like" and "reblog" buttons.

Vuvox  SHUT DOWN IN 2013.
Multimedia collage tool. Photo slide shows, video, photos. Can’t post directly from Vuvox. Post elsewhere then embed in blog.