4Videosoft iPhone Ringtone Maker can help iPhone users to convert MP3 to iPhone/iPhone OS 3.0/3.1 Ringtone, even convert any video/audio to iPhone M4R Ringtone, including 3GP, AVI, MKV, RM, MOV, XviD, MPEG, WMV, DivX, MP4, etc to M4R iPhone ringtone.