When Apple announced that users could get custom ringtones for 99 cents (on top of the 99 cents to purchase a song), many users were upset.

That lasted a few days as today, a blogger discovered how to make custom ringtones for free and get them on the iPhone. Hit the cut for the steps:

Blogger gryphondwb figured out this sequence of steps for custom ringtones. This requires the newly released iTunes 7.4. MP3 files must first be converted to AAC, which iTunes will do.

gryphondwb's method:

1. To add a ringtone to your iPhone, using Windows Explorer or the Finder just duplicate and rename any AAC file to be "M4R", then double-click on it. This file will be added to your iTunes library automatically.
2. Now, click on your iPhone in iTunes, and go to the ringtone section. You should now see your new ringtone. If you want to be sure about the sync, feel free to click "selected ringtones" and check off the file explicitly, though this shouldn't be required.
3. Now SYNC your phone. You're Done!

Excellent!

gryphondwb's Xanga: iPhone / iTunes - How to Add Ringtones for Free