Editorial disclaimer here - I have my own Spry/CF framework (cfspry), so I fully admit I came here looking for good ideas to improve my own code!
Covering Spry and AJAX, what makes widgets tick, and creating them with CF. No JavaScript will be used! He is covering Spry. (I won't copy too much of this down as Spry is a whole topic to itself.)
This review will be a bit short as I lost my original review. Andrew covered how you could move a static HTML page that generated Spry widgets to a completely dynamic one. The first iteration simply replaced hard coded data with data returned from a CFC. He ended up with a completely custom tag based solution.
His framework includes support for both widgets as well as Spry form validation (which is something I haven't yet added to my own custom tags).
I couldn't find a proper URL for his code, but this blog entry has a download: