It would be interesting to hear what is used besides sketches from UX engineers during development of a GUI. Unfortunately our UX team provides just a minimum of requirements for GUI screens. I believe that a better solution would be to use some tables with requirements and state machines or may be just some text description of GUI behavior? Is that something you use ?
I tried speaking to our UX team but looks like it's impossible to get anything besides graphic sketches from them and I am wondering what others use.
Our project is for iPhone currently, but it is could be useful to hear any advice even if you develop for any other platform or even desktop or web.