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.
The converter is pretty fast: it converts about 800 books per minute on a Mac Pro with 8 cores.