AT&T's network can't handle large crowds

Seth Bloom, a spokesman at AT&T, told GigaOm that the carrier is adding capacity to the downtown Austin network, and attendees should see their iPhone (or other AT&T device) experience improve by this evening.

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.

Heads up to AT&T: There's a big press event in Cupertino tomorrow and lots of iPhones will be there. I'm just sayin'...