Have you had a chance to play with Prezi.com
This is such a great tool but I have to say it wasn't easy to work out the first time I tried.
To view an example access: http://prezi.com/dav5xab3temw/
So what makes this product so unique?
First of all it is a simple registration. There is no special software required and there are no slides. Sessions can be created online and then downloaded for use as a flash type movie (downloads as a large zip file) without needing the internet to play.
The downside was it was not easy to work out and beginners can have problems with the screen enlarging with no way to actually get back to a smaller screen (my tip save and close your file and re-open it again). There were no written help instructions that acted as a how to guide but there are a multitude of video files you can watch to learn how to use it.
Another problem is when you click on the screen it changes the view of your document. Most of the time it became quite small and it was difficult to revert back to normal size. My tip here also is to refresh your screen until you become familiar with Prezi.
Another way to resize your text is to click on the Place circle and click on the text you will see a large blue circle with lines going different directions to indicate different parts of the circle. Point to the outer edge of the circle, hold down your left mouse and spin your circle and your text will rotate.
If you point to the next layer of the circle you can enlarge or decrease your text size.
If you point to the inner circle you can move you text around your screen.
To help my teachers use this tool I developed a simple PDF how to guide.
If it is of use I can send it to you.