I sent my Gmail account a 53kB AMR sound file (about 1 minute of audio) from my phone and when it showed up in my Gmail inbox the attachment was a ~512kB WAV file (mono, 8-bit).  I checked my phone to make sure it hadn’t auto-converted the file before sending it and it says it didn’t.  This means Gmail could be a handy part of an AMR-to-podcast solution.  Besides its conversion and email gateway roles, it would serve as a handy data archive.