alistairphillips.com

If you're wanting to use a pre-paid AT&T SIM on an Apple iPhone you'll need to beware of the fact that the carrier file the phone has prevents you from editing APN details. So to counter that you'll need to note the following steps:

• Using the iPhone Configuration Utility create a new configuration file called "AT&T PAYG" and identifier of com.alistairphillips.attpayg using:
  • APN : wap.cingular
  • User Name: wap@cingulargprs.com
  • Password: CINGULAR1
  • Proxy wireless.cingular.com port: 80