CNBC Contributor Kabir Sehgal just spent three mind-bending days at "Summit at Sea," a conference of entrepreneurs and game-changers on a charter cruise ship. Speakers included Google's Eric Schmidt, Uber's Travis Kalanick, Martha Stewart and more. These are some of the most intriguing ideas that he heard. Full report:
  1. De-extinction of woolly mammoths
    Author and biologist Stewart Brand spoke cogently about how humans could use advances in synthetic biology to bring an extinct species back to life. He said the DNA of woolly mammoths have already been sequenced and could be used to resurrect the species.
  2. The end of mass incarceration
    John Legend and Harry Belafonte spoke passionately about how the arts can be used to focus people's attention on burning issues of the day such as mass incarceration. They were joined onstage by bestselling author, lawyer, and social-justice advocate Bryan Stevenson. The goal is to create enough of a consensus to change sentencing guidelines. Both Legend and Stevenson have been meeting with prosecutors to explain their vision.
  3. Driverless cars
    Kalanick, in a conversation with Schmidt, said he's a believer in the future of driverless cars. He sees Uber as a technology company and has a vision for how the company would evolve in a driverless world.
  4. Equal rights for transgender individuals
    Transgender model and friend Geena Rocero joined me for lunch and explained that she thinks the next big thing is realizing true equality for transgender individuals. She grew up in Manila, Philippines, and became an internationally-known model who delivered a TED talk in 2014 that has garnered more than 2.7 million hits. She said that far too many transgender individuals face discrimination around the world.