Warren created the PostSecret project, in which people anonymously wrote a secret about themselves on a homemade postcard with no return address and mailed it to Warren. He then presented the postcards and their confessions on the PostSecret website, which was spun off into a very popular discussion forum and eventually a book. At SXSW, Warren presented many of these secrets to the live audience and discussed the project and his goals for it. A highlight of the session was when during the time when audience members were allowed to share secrets, one man took the opportunity to propose to his girlfriend.