I GOT IT! With a lot of fiddling and a lot of googling, I found out how to tether with TMobile USA....
I only tried it with Bluetooth and havent tried with USB.
You do need to download one thing though. Its a small script that needs to be put into ~/Library/Modem Scripts. Here is a link to download it.
Click Here
Alright here is a step by step as far as I can remember how I did it...
1. Pair the unit with your mac
2. Goto System Preferences>Network. Under the drop down menu for "Show:" select Bluetooth.
3. PPP Tab
- Account Name: <Enter in your mobile phone number>
- Password: <Enter in your mobile phone number>
- Phone Number: wap.voicestream.com
4. Bluetooth Modem Tab (This is why you needed to download that script!)
- For the drop down menu select BlackBerry 3G CID1
- Select "show modem status in menu bar"
5. Press Apply Now on the bottom.
6. Click on the phone icon on the menu bar and click connect
7. You should be on the internet!
That is everything I did to get the thing to tether. I did a speed test at Speedtest.net and got 160kbps/80kbps.
If I helped anyone here and they feel like helping me out, someone please tell me what #777 is. Because when my phone dialed that when i was following the OPs directions, someone picked up which scared the crap out of me and I quickly hung up... I think I heard, "Hello, this is <something something> how may I help you?"
EDIT: Oh by the way, I did it on my Tmobile 8800 if that makes a difference...
EDIT: Original script(s) can be found
Here from Ross Barkman