I have been a fan of Prezi for some time now. I like the way that it enables the author to pull out to look at the big picture and then to zoom in to investigate detail. We do need to be careful not to abuse it like we did with powerpoint. I have a discussion with my students that it should only be used when looking at both the big picture and detail is necessary for the presentation, otherwise just use a linear presentation tool.
Anyway Prezi recently released an upgrade that allows users up to insert up to 12 different diagrams.