At Synergy 2011 I gave a presentation on JSON, however by the end I suspect that I had bemused, rather than enlightened, the majority of the audience. (By diligently asking around, I was able to find about five people who were prepared to say they had grokked what I was on about... not so good out of around 80 in the hall! )
To try and make amends for this, I have published a much more fully explained example on Unicorn's web site, which can be found under Portfolio->Sample Applications as "VDF Ajax JSON Interface Sample". As well as the explanations, there is a full sample application which can be accessed from there.
I hope it helps to clarify what I was talking about in Orlando.