Free Event. Biz Stone is co-founder of Twitter, a real-time, one-to-many network that is changing the way people communicate around the world. Previously, Stone helped build other popular social media services Xanga, Blogger, and Odeo. After launching the journaling service Xanga in 2000, he went on to publish two books about the origins and social significance of blogging. Advance online RSVP is free but required.