Based on information provided by several tipsters, Engadget Mobile reported moments ago that various parts of Texas may be experiencing outages with AT&T.  Apparently, the issue centers around the phone being able to authenticate to the network.  An AT&T official statement claims that the outage will be resolved by the end of today:

"Due to an equipment issue, some AT&T mobility customers in Texas may be experiencing authentication issues with their wireless devices. AT&T technicians are working to resolve the issue at this time, and we expect service to be restored later today. We will provide more information as it becomes available. We apologize for the inconvenience."

We will keep you updated as the news breaks.