South By Southwest By Twitter

AUSTIN, Texas (Fortune) -- The recession hasn't dampened the mood ­ or attendance ­ at "Spring break for geeks," a.k.a. the annual South By Southwest Interactive conference. Organizers say the crowd will surpass last year's attendance of about 9,000.

Judging by the folks already here, a good number of those people will be brandishing Apple iPhones and Twittering incessantly. And quite possibly they are Twittering about service problems they are experiencing on the AT&T phone network that supports the iPhone (a sampling of the comments here and here).

AT&T (T, Fortune 500), which is based in Dallas, responded by adding capacity and responding to bloggers over the weekend.

Perhaps the telecom giant didn't expect so many tech types to descend on Austin, which also hosts a music and film festival at the same time. In the past, many attendees traveled on corporate expense accounts. This year, with travel budgets slashed, a good number of conference-goers paid their own way, a testament to the quality of the event. One attendee called it the "world's biggest career fair."

For the suits in attendance, the conference is a chance to better understand the trends taking the web by storm.

"One of the differences between this year and years past is that pretty much every hour there's a panel on how your company can use Twitter," says Dennis Crowley, who launched his new mobile social networking product Foursquare at the conference to much success.

Adds Crowley: "In the past it was filled with scrappy startups, now I recognize fewer and fewer people. There's a lot of khaki pants and untucked shirts."

Indeed I've come across quite a few newcomers to SXSWi who have been asked by their companies to add "oversee social media." They look slightly scared.