One of the most useful teaching tools for history teachers are time-lines.
The best free timeline builder that I’ve come across was XTimeline. If you have a blog or website for your class, you can easily embed a timeline into your class site.
For student presentations you can also encourage students to create time-lines. For example, if a student is doing a presentation about Terry Fox, one can create a time-line outlining his journey across Canada. It is an effective tool for learning and retention.
You can also encourage students to work on a group project using this teaching tool. XTimeline allows users to collaborate in a similar manner to a wiki. The multi-media that can be added includes video, text and images.