Sorry to be bringing an old thread back from the dead. I thought I'd just register to let people (especially the googlers, like me that land on this page because of the m510 query from the previous poster) know that yes, this process does work for the m510 and possibly newer too.

I got my m510 this weekend, and I have a custom ringtone for it thanks to this thread.

I used the Super process, and will be trying later with the Audacity/Super process to encode a few old mp3s of our band.

See More: Here's how to make your MP3s into ringers on your M500