Easier Flex UI Building with Fireworks 3
I've never been a big fan of Fireworks, so haven't used it very much. Once I saw the MXML/Flex export from Fireworks 3 back in beta, however, I was very impressed and finally saw a use for the app. In a nutshell, you can prototype Flex UIs using Fireworks and then export the MXML from Fireworks and add your logic in Flex Builder (or whatever else you choose). Pretty handy.
What I didn't know was that you can do a lot more than just lay out the MXML. You can do a lot of styling work in Fireworks (where some tasks are easier than in Flex Builder) and then also export that information as well. Peter Baird wrote a good, short article on how to use Fireworks 3 for Flex UI prototyping on Adobe's Developer Center.
I don't do a ton of UI design work myself (I have great people on staff who are so much better at it than I), but when I do need to lay some stuff out, Fireworks is a handy tool — especially for prototyping and hiding and showing layers of the UI really quickly. There's even a Flex Style Explorer for Fireworks which helps to make sure that the work you do in Fireworks translates seamlessly over to Flex. Again, very handy.

