Nice work Paul W. and Pullo - excellent series of posts.
While I'd agree with Paul O'B that the non-jQuery version doesn't look simpler/shorter, it is definitely worth noting that the bespoke code here will have a few benefits to it. It will perform better and be easy to maintain even by someone who doesn't have any knowledge of jQuery. It would also be quite trivial to turn it in to it's own little extendible library that can be included in other places.
Looking forward to seeing more of these quiz/competition things :)