I have tried several ways of tethering my Mac laptop to my Android phone, but I think that USB is the most effective one, at least from a subjective point of view: it doesn’t use as much battery as Bluetooth or WiFi tethering, it seems safer from a security point of view since it transmit the data over a cable, and it also seems safer from a health point of view as it does not rely on yet another wireless emitting point.
In order to get Mac OS X to tether with my Android phone over USB, I had to install Joshua Wise‘s HoRNDIS. It is a Mac OS X package that implements a kext RNDIS driver. The beauty of it all: it is open source and straightforward to set up and use: download the package, install it, connect your Android phone to your laptop using an USB cable, enable USB tethering and it should work automatically, without having to do anything. Magic!
PS: A copy of the HoRNDIS release 4 package can be found here.