Using Iphone as bluetooth replacement for mac I have a late 2011 mac book pro with bluetooth 2.1 which works terribly with my speakers. Is there anyway I can use my Iphone 5s with bluetooth 4.0 as a sort of replacement. Through USB, WIFI or Bluetooth?
I don't think it's possible to use the iPhone as bluetooth bridge between your macbook and the speakers.

The cheap alternative is to buy a bluetooth dongle like this one:

ASUS USB Adapter with Bluetooth (USB-BT400)