Sometimes there is a need to convert audio files from the AAC format (as used by Apple’s iTunes Store) to the more commonly used mp3 format.
I for instance had to do this to listen to music which I put on a usb memory stick for usage with my car entertainment system.
Anyways, to make the process simple I have created an Automator workflow which recursively finds all .m4a files in a folder, encodes them to .mp3 and then deletes the original m4a file (I told you!). This all with Mac OS X built-in tools.
m4a-to-mp3 as Mac OS X App
PS: Due to some stupidity I lost the actual editable workflow file … sorry!
PPS: I’ve learned that just changing the file extension might have been enough for my use case.