Enabling iPhone 3.0 Tethering

This has nothing to do the iPhone SDK but there seems to be enough interest in getting tethering function on iPhone in the US on AT&T.
The information here has been validated by a few iPhone users that I know personally. They have tethering working and are quite happy with the results.

NOTE: These steps work at the time of this writing and my not work with future versions of iPhone 3.x OS.

The simplest way to enable tethering is to go to navigate to the following site on your iPhone.

The follow the instructions to enable tethering. Following this you will notice that your Visual Voice Mail is no longer functioning. Which can easily be resolved by the following simple steps.
1) Reset Networ setting on the iPhone from the setting page
2) Reset the Voice Mail password

Once you have done this you will once again have Video Voice Mail along with tethering.
Hope this helps.