Prezi is a neat presentation tool that kids can use as an alternative to keynote or powerpoint. What I really like about it, is that it is not slide based as are most presentations. Prezi is a flash based application that allows you to create non-linear presentations where you can zoom in and out of a visual map containing words, links, images, videos, etc
The interface itself is pretty intuitive, once you've worked out how to manipulate the "zebra" I had a play with it the other day and in no time I had made my first presentation. As with most of these tools, you can sign up as an educator (school website url and email address required) and then you are set to create an account for your class to use.
A number of my students were pretty keen to use this tool to showcase their most recent learning. Here is an example of a student's cultural heritage presentation.