No doubt some of you will know of this, but Prezi is a fabulous (relatively) new online platform for making presentations. It builds the presentation from a 'mind map'. Very compelling, and it's remarkably simple to put these presentations together from your browser. Check out this presentation on the new economy which is pretty interesting in and of itself. But it's a fabulous illustration of Prezi's capacity to visually represent the structure of an argument, the relationship between the slides or the elements of the argument.