Can anyone recommend some free webspace for me to store a mix so people can listen to it?
No idea for free 'audio' webspace these days.
Seems paying is the only way to go these days for decent audio hosting.
Once our server is up and runnin, we might be opening a few accounts to 'friends' on a yearly pay basis. It should be a lot cheaper than anywhere else, I will let you know more once we have it all finalised.