Just build it
With AJAX and DOM scripting becoming more commonplace, pages are too dynamic to illustrate with a static wireframe or page description diagram, and it seems everyone is starting to realize it. Unfortunately, The [sic] alternatives to traditional wireframes such as animated GIF's [sic] or storyboarding, really aren't much better. I really think there's only one solution. Just build it.
— Garrett Dimon, AJAX & DOM Scripting: Just Build It (emphasis his)