Converting from m4a to mp3 on a whole bunch of files recursively
Convert to wav first:
find . -name \*.[Mm]4[Aa] -exec faad {} \;
Clean up the m4a's:
find . -name \*.[Mm]4[Aa] -exec rm -rf {} \;
Convert to mp3
find . -name \*.[Ww][Aa][Vv] -exec lame {} \;
find . -name \*.[Ww][Aa][Vv] -exec lame {} \;