The Online News Association, the world’s largest membership organization of digital journalists, today announced tech broadcaster Leo Laporte as the third keynote speaker at its Oct. 1-3 conference in San Francisco. Laporte joins Twitter CEO Evan Williams and Lisa Stone, CEO of Blogher, who are also headlining the event.

The 2009 conference, which marks ONA’s 10th anniversary, is expected to attract hundreds of digital journalists from around the world for three days of leading-edge panels and workshops, the popular Multimedia Learning Lab and a new Career Summit and expanded Job Fair. Last year’s event in Washington, D.C. sold out early. ONA09 concludes with the presentation of the Online Journalism Awards, honoring excellence in online journalism.

Laporte hosts “Leo Laporte, The Tech Guy,” a national radio technology talk show, every Saturday and Sunday from 2 to 5 p.m. (ET) on the Premiere Radio Networks, which include XM Channel 158. He also appears regularly on television and radio programs, including “Live with Regis and Kelly.”

“Leo is known as ‘The Tech Guy’ for good reason,” said ONA President Jonathan Dube. “Not only does he cover technology, he puts it to good use. He’s a great model for entrepreneurial journalism.”

Laporte hosts and produces some of the most popular podcasts in the world, including This Week in Tech, Security Now!, net@nite, The Daily Giz Wiz, Windows Weekly, MacBreak Weekly, Jumping Monkeys, and Munchcast under the TWiT banner.

In May 2008, Laporte launched a live streaming video version of TWiT called TWiT Live, which features 25 hours of original programming each week. More than 2.6 million people watched TWiT Live in its first month.

Laporte began his career in radio broadcasting, but went on to write everything from computer software to books. “Leo Laporte’s 2003 Technology Almanac” was Pearson Publishing’s Book of the Year in 2003. His television career includes “Internet!,” a weekly half-hour show on PBS, and “The Site,” an hour-long technology newsmagazine for which he won an Emmy in 1997.

Laporte will join Twitter’s Evan Williams and Blogher’s Lisa Stone as keynoters at ONA09.

Williams is the CEO and co-founder of Twitter, the fastest-growing social network where users answer the question, “What are you doing?” in 140 characters or less.

Lisa Stone is the CEO and co-founder of Blogher, an online community for women. Begun as a labor of love in 2005 as a conference for women bloggers, Blogher is now the No. 1 community of blogs by women, reaching more than 14 million women each month via annual conferences, a Web hub, and a publishing network of more than 2,700 blog affiliates.