if you have internet on your cell, you can create your own mp3's and host them on geocities for example, than with your cell, you write the url , and the song will download on your cell phone...but you must have the mp3 on your cell and I think you need something like WAP internet i don't know exactly
for myself, I took the chorus of Staring Through my Rearview, hosted it, and downlaoded it, now its my ringtone