Rumor has it that AT&T will officially allow "tethering" later this year, which will enable using an iPhone as a modem to connect laptops to the internet. If you do not want to wait, you can follow the following steps to begin tethering your Mac right now:
- On the iPhone, goto help.benm.at in Safari.
- On that web page, scroll down to Mobileconfigs –> Downloads –> USA –> ATT and install the profile.
- On the iPhone, go to Settings –> General –> Reset –> Reset Network settings (this step is to enable Visual Voicemail).
- Restart the iPhone just in case, especially if it does not reboot at this point.
- Turn on Bluetooth on the iPhone in Settings –> Bluetooth.
- On the iPhone, turn on tethering in Settings –> General –> Network –> Internet tethering.
- On the Mac, click on BlueTooth icon in upper right menu bar or in System Preferences –> Bluetooth. Choose “Set up a BlueTooth Device”
- Setup and pair the Mac with the iPhone, make sure the iPhone is in BlueTooth discoverable screen.
- Click on BlueTooth icon again in upper right menu bar, choose your phone from the drop-down menu and connect to network.
Source: "10 Steps To Turning Your iPhone Into A Modem For Your Laptop" by Eugene S. Melchionne, published at Legal Practice Pro.