Make a ringtone from any mp3 file in iTunes in under a minute.

Personal Note: I say keep it on vibrate most of the time out of politeness for the general public, but use the ringtones for your morning alarm!

1. In iTunes, find the song from which you want to make a ringtone. Write down the interval of time you wish to capture (e.g. the chorus from 1:13 to 1:27).

2. Right-click on the mp3 file and select ‘Get Info’.

3. Go to the tab for ‘Options’, check the boxes for ‘Start Time’ and ‘End Time’, and input the interval you wish to capture in your ringtone. Hit ‘OK’.

4. With that mp3 file still highlighted, go up top to the ‘Advanced’ menu and select ‘Create AAC Version’. This will automatically create a new file in your library (and it should have a length equal to the interval you set previously).

5. Drag and drop this new AAC file to your desktop. It should have a .m4a extension.

6. Change the extension of this file from “.m4a” to “.m4r”.

7. Drag this file from your desktop back into iTunes. It should now be available in your ‘Ringtones’ library on the left. If you don’t see this library, got to Preferences and make sure you have checked the box to show this library in your iTunes.

8. Lastly, you can delete the file on your desktop, and can delete the AAC version of the song in your iTunes music library. Also, remember to change the original mp3 file back to the normal start and end times (just unclick the boxes).

9. Sync your iPhone/ringtones and you’re good to go.

Reference: eHow