On older version 1.x firmware, there were some nice tools to let you use any music as a ringtone. Wiped out with 2.0 arriving. And who wants to pay $1 for a ringtone when you already own the music. Some “solutions”:http://www.macnn.com/articles/08/07/01/ringtones.for.iphone/
For the total roll your own, “eHow”:http://www.ehow.com/how_2160506_custom-iphone-ringtones-garageband.html shows you exactly how you do it with Garageband. You basically have to use the “Cycle Region” button to get the 40 second clip that you can use for a ringtone and then Send it to iTunes. Couldn’t be easier! _Only problem for me is the ringtones don’t seem to show up anywhere on the iPhone. Sigh_
I haven’t tried it but “Pocketmac.net”:http://www.pocketmac.net/products/ringtonestudio/indexp.html has a $15 tool that let’s you use unprotected music as ringtones.
If you love danger, “iRinger”:http://www.techmixer.com/free-iphone-ringtone-maker-with-iphone-3g-supported-using-iringer/ is a freeware program that does this as well. It only runs on Windows though 🙁
However it also turns out that the “easy”:http://www.iphonefreak.com/2008/03/free-ringtones.html way to do this is to take your MP3 convert and edit it with Garageband or Audacity to 30 seconds as an MP3. Then open iTunes and right click on the song and export it into AAC format. Then go to the music folder and rename it from a M4A to a M4R extension. When you readd this to iTunes, you can drag it into the ringtone section.
Of course, the easiest way if you have a Mac is to load Garageband, drop an MP3 on it. Then edit it down to 30 seconds and choose Share/Export Ringtone to iTunes 🙂