Okay I did a little bit of testing with the Simulator and SnapperMail. If I email myself a midi file, one of the options for the attachment is "Open with Sounds" which allows the file to be put in the list of possible ringtones to choose from. When I attempted doing the same with a wave file, it didn't give me any options for opening. This leads me to believe that the Treo 600 will not natively support wave ringtones.

My question is for all of the programmer types out there. With the release of all the Audio APIs by Handspring, will someone eventually be able to write an app that lets wave files be used as ringers, or is this a case where if it can't do it out of the box, its impossible?