Chronozoom is an open-source, interactive timeline tool. It has some curriculum developed for social studies but the timeline spans from the Cosmos to Humanity. It moves similar to a Prezi, and it is possible for students/teachers to develop their own timelines.

Historypin (http://www.historypin.com/) allows users to post photographs, audio, and video files to different places in the world. It provides primary sources about areas, historical and present day. It could be used for research or collaborative projects by students.