After a first review of Prezi and pptPlex I started to get into a more detail with Prezi. One of the applications of these zooming tools is to create an effect of a perpetually zooming canvas. (There is a series of children books that uses this effect brilliantly.)
You can see my Prezi creation here (put together very quickly). Zoom out with your mouse to get the full picture. All images were taken from iStockphoto.