Sending custom made ringtones

Is there a way to edit a song and send it to my Japanese cell phone to use as a ringtone? I used to be able to do it with an older model, but my current AU solar phone (SH002) won't open wav or mp3 files. What file type does it use?

It's mmf.
Here's a free service to convert mp3 to mmf.
http://3gp.fm/

Also there are free softwares available to convert wav & mp3 to mmf files.
http://freesoftdownload.1-yo.com/mobile/chaku-uta/mmf-esechaku-uta.htm...
just for example.

Thanks!!

sorry, nevermind. It plays on my phone fine, but I can't set it as a ringtone for some reason...

... i got the えせ着うたフロントエンドSMAF版 program and after an hour found the SscMA3 program needed. The other link you gave me plays on my phone but isn't acceptable for a ringtone.

The sound works as a ringtone, but sounds really compressed. I'll have to mull it over a bit more.
Thanks for the help.