From Ringtone4Me:

Mobile Music Polyphonic is a polyphonic ringtones composer and converter, which allows you convert midi, mp3, wave, mmf, avi, rmvb, rm, wma, wmv, mpeg to cellphone polyphonic ringtone format (smaf(*.mmf), amr-nb, amr-wb, amr-wb+, sp-midi. You can convert midi to mmf, midi to sp-midi, mp3 to mmf, wave to mmf, wave to amr, also mp3 to AMR, amr to wave, amr to mp3, amr to wave, mp3 to wave and wave to mp3. Convert between mmf, mp3, wave, amr-nb, amr-wb, and amr-wb+ format. Convert mp3/wave/amr/awb to mmf. Sp-midi is nokia ringtone format and more cellphone brands polyphonic ringtone format. Support Nokia, Sony Ericsson, Samsung, Siemens and more brand polyphonic ringtone mobile phones.

* Convert mp3 wave avi rmvb midi to m4r - iPhone ringtone format.
* Compose your own music by click mouse, setup different key signature, clef and meter. Setup score tempo.
* Seperate several midi channels from many complex channels midi file
* Save part midi data from long complex midi file.
* Setup music instrument to every midi channel.
* Compose any complex music sheet, including channel position, volume, priority in sp-midi.
* Convert midi to mmf, midi to mp3, midi to m4r.
* Convert all audio/video to m4r iphone ringtone format.
* Convert wave to AMR, mp3 to AMR, AMR to wave, AMR to mp3, MP3/WAV/AMR to AWB.
* Convert mp3 to mmf, wave to mmf and mp3 to wave.
* Convert between mp3, wave, mmf, amr, awb, midi.