Apple iPhone now officially supports ringtones but require you to pay and purchase them from iTunes Store, However, you can easily create and use custom iPhone ringtones from your existing MP3 music library for free, there exist several different tricks and utilities to create iPhone compatible ringtones with ease.

Ring Ring would be the most easy to use free utility for creating custom iPhone ringtones, to convert any MP3 file into iPhone compatible ringtone format all you need to do is to simply Drag-and-drop it into the application and choose start and stop timings, details of the full procedure are as follows:

1. Download and Extract Ring Ring - iPhone Ringtone Maker.
2. Double-click "RingRing.exe" to launch application.

3. Drag-and-drop or Double-click and browse desired MP3 file from the Drop-target as shown above.

4. Select ringtone Start and End timings as shown above.
5. Preview (optional) the output and click "Create Ringtone!".
6. After processing, the directory with your ringtones in .m4r format will open.

7. Double-click or Drag the output file into iTunes, your ringtones should now be visible in iTunes under Ringtones Tab and can now be synced with iPhone.

Download:

RingRing - iPhone Ringtone Maker [496 KB]>>

Application Author - Franklin Webber

You can alternatively use the method shown below to create custom iPhone ringtones using nothing but iTunes 8: