It's no secret by any means - ask anyone that has AT&T and is attending SXSW and they're not pleased, to say the least.  Since the onset of the event, wireless service has been shaky at best, in part because of the influx of iPhone 3G devices in the area.  AT&T is aware of the problem, and says that service in Austin, Texas should be better as of today:

"To accommodate unprecedented demand for mobile data and voice applications at SXSW, we are actively working this afternoon to add capacity to our cell sites serving downtown Austin.  These efforts are ongoing, but we anticipate that customers should see improved network performance this evening and for the remainder of the event.  We will continue to monitor network performance throughout the event, and will do everything possible to maximize network performance throughout.  We apologize to customers who were inconvenienced during this surge in local network demand."
AT&T, March 15, 2009

So, according to AT&T, everything should be all better now.  Shoutout to anyone at SXSW - is anyone still experiencing call/data issues?  Please let us know!

Source: The Business Insider