We mostly use FireWorks for UI design and believe that it's the best tool on the job. Despite obvious Adobe indecisiveness on what to do with it and absence of any serious updates or bug fixes FireWorks is still the most powerful and useful app when it comes to web/GUI design. Here is a list of resources that may help you to optimize your workflow and extend Fireworks functionality:
Freebies and downloadable resources:
Extending FireWorks functionality:
To be continued...