2012 UPDATE: If you have not made a Prezi in the last 6 months, it is time to give this amazing, free resource another look! The 3D backgrounds, improved design functions and ease of use make if better than ever!
2011 UPDATE: Prezi just keeps getting better and more perfect for classroom use. One year or so ago they did a MAJOR overhaul that made Prezi BETTER and MUCH EASIER to use. Prezi added FREE Edu account that let you and your students create private Prezi presentations. Now they have VASTLY improved the collaborative power of Prezi with Prezi Meeting.
With Prezi Meeting your students can collaborate in real time with kids across the classroom, across town, or across the globe to brainstorm and build a Prezi . Once they are ready, they can collaboratively present their project online - even if they are half a world apart. Very cool.
Every once in a while you find a truly transformative tool. Prezi takes PowerPoint and SMART and all of the other "presentation" tools and flips them inside out. Check this out and fall in love with the power of this incredibly engaging presentation tool. I wish every teacher at my school was using Prezi. It is amazing!
Here is just one example of Prezi made by a colleague of mine. (Thanks Jen!) There are thousands more on their website.