I recently attended the Sloan-C International Conference on Online Learning. In one of the presentations I attended, the presenters used a fascinating and quite effective presentation tool called Prezi. I talked to them afterward and found that they thought it was easy to learn, easy to use, and there is a free version. I have since tried it out and I like it!
Prezi basically allows you to create your presentation as a sort of mindmap, and then it handles all the zooming and panning during the presentation. Check out this example to get a flavor of how it works: http://prezi.com/a4p1e8jzgutl/view/#90. After you open the page, click on the Play button at the bottom right to advance the views. But as you can see, you are displaying subsequesnt zoom-and-pan views of a single large canvas. Kind of cool!
Here is a short video showing what it’s like to create one of these presentations: