Prezi allows users to create dynamic "zooming" presentations. If you have already created a PowerPoint presentation, it also offers an option to import your existing slides to Prezi. Presentations are created, stored and delivered online, but premium subscribers also have the option for an offline version of the tool. The tool offers both free and pay versions and students and professors are eligible for a free educational account with some additional features. Please also note that Prezi is not currently accessible to those using screenreaders.
Prezi also offers mobile apps for those who want to use view or display their Prezis on the go.
This add-on for Prezi will allow you to embed a realtime Twitter search in your Prezi. Use it to take feedback or questions from your audience or to see recent tweets on any topic.
Prezi offers a large number of tutorials to help you with every step of the process on their YouTube channel. The video below shows how to get started. You can also find examples of Prezis in their gallery.