Sorry, can't help you, but I would like to let other readers who may be thinking of getting the Samsung S3 that there is a BIG learning curve verses the IP. I bought one at the beginning of September, mainly because I thought it suppored Flash (which it may do), but I was unable to get on some flash sites with the phone.
The phone comes with almost no documention. There is a very basic programed learning site on the web, but it didn't help me. After 2 weeks, I took it back to the store, paid my $35 restocking fee and bought an IP5, which IMHO is the best IP ever and beats the S3 in all areas except screen size.
I was able to tether my IP5 in about 2 minutes or was it 30 seconds?
@blueeos would be nice if you actually answered the OP's question rather than go on a sales pitch.
Tethering with an Android phone is just as easy as with an iPhone. If I remember correctly, on Android 4.0 the menu item for it is located:
Settings -> More Settings -> Tethering and Portable Hotspot -> USB Tethering/Bluetooth/Wifi Hotspot.
On your Mac, in System Preferences, Go to Bluetooth. Click the ( + ) on the bottom left. Just go through standard bluetooth pairing.