Fireworks vs Axure

From lo-fidelity wireframe, into clickable prototype and then assemble the images for the final hi-fi build as well.

Features such as 'Layer Sharing' allows you to quickly update shared components such as headers across multiple pages. Other mockup tools such as Mockingbird will require you to manually propagate changes across all the pages.

Open PSD files

A significant advantage over web-app style mockup tools are the symbol libraries for Fireworks.

From boagworld:

Both symbols, styles and vector shapes can be saved for re-use and collected into useful library resources. In addition Fireworks ships with a common library of useful objects including buttons, browser and application elements for both Mac and Windows look and feel.

http://speckycdn.sdm.netdna-cdn.com/wp-content/uploads/2010/10/ui_templates_02.jpg

Allows creation of interactive HTML mock-ups which is accessible for both websites and mobile applications.

Great web options, but you can also save your wire frames out to Word and convert the notes to annotations.

You can create a component (widget) that you can use over and over again.

Available for use on Windows and Mac.

You can set up a project with SVN-like check-in/out system to work with others.

There is a wealth of online training including videos for getting the basics down, a great community to mine, and support team to help assist with more technical details.