I've just released a new plugin that exposes an "onfontresize" event on the document object.
It's based heavily on a technique created (AFAIK) by Hedger Wang which you can read about here: http://www.hedgerwow.com/360/dhtml/js-onfontresize.html I made some minor tweaks and packaged it up as a simple to use jquery plugin which you can find here: http://tomdeater.com/jquery/onfontresize/
