DIY Ringer For iPhone UPDATED x2

1. Make sure the sound file is in AAC format. If it's not, you can use iTune to convert it.
2. Use iTune to crop it down to about 30 secs, this is optional but really, kinda useful.
3. Copy the result file out, you can do that via drag and drop.
4. Rename the file extension from m4a to m4r. On OSX, this is more tricky than you may think. Beacuse by default, it hides extension. So you THINK you renamed it, but you didn't. The sure fire way is to do a "Get Info" on the file, go down to "Name and Extension", and change it there.
5. Doubt click on the result file. It will show up now on iPhone ringtone tab when you plug in your iPhone.

Looks like someone else discovered first. The first publication of this trick was at a macrumor thread.

iTunes 7.4.1 breaks it, don't update.