FB2 to iBook converter takes an fb2 file with an eBook and creates a file in epub that iTunes and iBooks can understand. It transfers the metadata from the fb2 file, maps the cover (if there is one). The converter can read individual fb2 files or fb2 files stored in zip archives. Requires Mac OS X 10.6 or higher.
Download FB2 to iBook converter
The converter is pretty fast: it converts about 800 books per minute on a Mac Pro with 8 cores.
Technicalities: The converter uses an xslt stylesheet and a css style file for the conversion. These files are located in the style package inside the application. You can create additional styles from the one provide with the application and put them into ~/Application Support/BookMania/Styles.