Efiko Software has announced that iPhoneRingToneMaker for the Mac OS X Leopard (and Tiger) is now available.
iPhoneRingToneMaker works with the iPhone 2.0 and iTune 7.7 updates. The app now sends your created ringtones to your iTunes Ringtones Playlist as opposed to directly to your iPhone to ensure that your ringtones will work in future iTunes and iPhone updates.
iPhoneRingToneMaker retails for US$7.50.
More info and free trial download link here.