Those geeks tired of PowerPoint might want to try Prezi, an online tool which allows you to create intuitive presentations in a way similar to Mind Mapping. The service is very easy to use and you have both payed and free plans. The free one ads only a small, discrete watermark to your presentations, so you might want to give it a try.
I use a great free alternative http://www.ahead.com. 3GB storage and also great for creating zooming web sites, and handles rich media imminently.