Just as news hit that Twitter launched an updated interface, word also broke that the social network's CEO and cofounder Ev Williams stepped down from his current post. Lucky for you, Ev will be joining Biz Stone in a candid conversation hosted by The Commonwealth Club's INFORUM division on Columbus Day to answer all of your most burning questions.

Find out what these changes mean for the site that has more than 160 million users who send nearly 100 million messages a day. These two rarely appear in public together, so seize this opportunity now while tickets are still available. And for those passionate Tweeters out there, we're offering the chance to meet Ev and Biz up-close-and-personal. Send an email to events@7x7.com telling us how many followers you have, and the person with the most wins a pair of tickets and the chance to meet these guys live. No cheating—send us the link to your Twitter page so we can see for ourselves.

$15-$30+; Monday, 10/11 at 7 p.m., Julia Morgan Ballroom at The Merchants Exchange, 465 California St., commonwealthclub.org