faceyspacey : I don't have any code, because I'm not using C2 for that. I have a piece of Flash applet giving me a base64 audio string, and, in my index.html page, I do a simple
localStorage['mp3File'] = audioMP3.src;
to save the file (the .src being the base64 string), and I do just the opposite to load the file.
If you don't have the base64 representation of your audio file, you need to prepare it before creating your game. There are several binary <-> base64 encoders online, like there : http://www.motobit.com/util/base64-decoder-encoder.asp
Don't forget to have the right MIME type in front of your base64 string ! (Like
"data:audio/ogg;base64,"
for OGG)