Amadeus Pro plays nicely with iTunes. The File menu has an Export to iTunes library item that allows you to add the open document to your iTunes music library. It is recommended to set the metadata (song name, artist name, etc) prior to selecting this function, so that the song shows up properly in iTunes.
Next to this, there is a Export as iPhone Ringtone item that does pretty much the same thing, but instead of adding the document to your music library, it adds it to your ringtone library. Both of these functions were only tested with iTunes 8 and 9. They might not work correctly with earlier versions.
Warning: In order to work correctly, both of these
functions require the Copy files to iTunes Media folder when adding
to library
option in iTunes's Advanced
preferences to be
checked. (This is iTunes's default behaviour.) If this is not checked,
the files will not be added to your iTunes library.