Prezi is a free online service that you can use to create presentations as you normally would make in PowerPoint but more interactive and with a nice zooming effect. Instead of Slides, Prezi is completely based in the idea of a visual map and path.
Then you can apply some path movements and changes to rotate the visual map and navigate to the next content. Here are some of the main differences of powerpoint vs Prezi:
Another approach is to embed Prezi in powerpoint. For this purpose, the guys of SlideDynamics have created a plugin that will allow you to embed Prezi presentations inside powerpoint. Beside Prezi presentations, you can insert Web elements or Vimeo Videos in powerpoint presentations using this Addin.