UPDATE: Looks like with OS X Mountain Lion, you don’t have to do the following hack anymore! The Broadcom dongle I describe in this article is supported on OS X Mountain Lion by default! In fact, the new kext includes support specifically for the IOGEAR GBU521 Bluetooth 4.0 Micro Adapter! Also, you might want to consider getting the IOGEAR one since the eBay one I got has a bright blue LED that’s always lit and can be pretty annoying at More >