Like most good ideas, this is nice and simply, and before you all post "but it still gets your real address" re-read it, thats not what it's trying to do, you can afterall spoof MAC addresses very easily.
RMEMBER security that relies on one thing is not security, it's wishful thinking. This process, when used with common sense and other good security measures, is a very clever trick! http://www.theregister.co.uk/2014/06/10/ios_wi_fi_mac_address_trick/