Now I have a brand-new Samsung M510 that can double as an MP3 player. Of course, when it's busy playing MP3s, it won't actually pick up calls, which is a bit of a minus. But I have confirmed that I can get it to play an MP3, by the simple expedient of loading the only MP3 that I had handy on there.
Mich and Marilisa's "Go Home". :)