Timelines are for more than history class, they allow students to create a graphical representation of related events in sequential order. Timeline is a great web tool to use available from Read, Write, Think.
Projects are saved and loaded from personal files so there is no need for student accounts. Printouts are also available or students can email the finished time line to their teacher. The interface is simple to use.
One option would be to have students combine time lines into one longer series of events. Another idea would be for students to sequence major events in a story. They could also document their progress on a particular project. Science labs could document progress over time.
Students could list step by step instructions for completing a task. Another application would be planning a vacation or perhaps a multi-course meal. Anything that needs placed into sequential order would work well.
Timeline does require Adobe Flash, so it does not work well on mobile devices.