Benjamin Satterfield, a 33-year-old Internet entrepreneur, knows how fickle Web tastemakers can be.

Last year he introduced an online collaboration tool called Twiddla at the annual South by Southwest Interactive conference [in Austin, Tex.], which attracts thousands of influential Webheads. Twiddla won praise and even a prize at the conference's Interactive Web Awards. But the spotlight quickly faded.

"We had millions of hits to the site," Mr. Satterfield said. "Then it died off. I was in a trough of despair."

This year, he tried to build something that would be used long after the conference buzz died down. He created Gigotron, a free Web and iPhone application that rounds up listings of nearby concerts.

The service is already running in Los Angeles, New York and San Francisco, and Mr. Satterfield is about to take the wraps off a version tailored for the Austin music scene. "You know you're going to get traction at South by Southwest," he said.

Mr. Satterfield is one of many entrepreneurs who flock to the music and media conference in the hope of capturing the attention of attendees and elevating their product or service out of obscurity.

Twitter, the chatty Web service that is quickly entering the mainstream, first hit it big during the 2007 conference because of giant screens installed around the convention center displaying Twitter messages from the crowd. Shawn O'Keefe, who has been helping organize the tech-oriented portion of South by Southwest for nearly a decade, said that in the early days the conference also helped give a lift to the makers of the blogging tools Blogger and Movable Type.

But wooing the technorati is a tricky business. Start-up companies are aware that in-your-face marketing is a good way to scare off the kinds of people who go to South by Southwest.

JagTag, a company based in Princeton, New Jersey,...