Well, this is a handy (and well-timed) find! User Cleverboy over at Macrumors has discovered a simple trick to get your own music onto your iPhone using the just-released iTunes 7.4, and it'll cost you precisely nothing. To get this to work, we hear you only need to rename an AAC track to .M4R, then double click it and iTunes will automagically load it into iTunes for you. Next time you plug in your iPhone to sync up, just check off the song in the Ringtones tab and voila, instant tone gratification. Thanks, Apple -- free ringtones for the songs we already own or ripped from our own CDs, this is how it should have been from the get-go. On a happy note, Macrumor's forum users are reporting the magic works via both Apple and Windows flavors of iTunes, but feel free let us know how you all get on.