A wonderful tool that could be useful both for you and your pupils.

Prezi is a cloud-based (SaaS) presentation software and storytelling tool for exploring and sharing ideas upon a virtual canvas. Prezi is distinguished by its Zooming User Interface (ZUI), which enables users to zoom in and out of their presentation media. Prezi allows users to display and navigate through information within a 2.5D space on the Z-axis.

(Wikipedia)

Here is an example of presentation you can do with Prezi, and it is FREE!!!!!!!!!!!!!!!!!!