A little known fact (at least it was to me until someone pointed it out) is that you can make anything you want into a ringtone for your iPhone. All you need is GarageBand '08 or '09 and iTunes, which, if you have a mac, you probably do. Not sure if there is a way to do this on a PC, so sorry about that. But here's how to do it on a mac:
1) Download the ringtone from here and unzip it.
2) Open GarageBand. Drag either the mp3 or wave (if there is one) into the big space in the window, creating a new track.
3) Click the cycle button. This is how you decide how long your ringtone will be.
4) Drag the edges of the cycle bar (in yellow) the beginning and end of the ringtone file. It won't let you ringtone-ify it without this step.
5) From the 'Share' Menu, choose 'Send Ringtone to iTunes'. And that's it! It will name it in iTunes whatever the GarageBand file is called, so you can rename it in iTunes to be more descriptive if you need to.
6) Sync your phone. Voila!
You can save this GarageBand file or not, it doesn't matter b/c now it is in your iTunes collection, and properly registered as a ringtone. I believe that internally it is really just an AAC file, but if you try it any other way, it will end up in your music collection, not your ringtones. Unless your phone is unlocked, but I don't know anything about that.
