Shiza Shahid

Entrepreneur, Technologist, Investor, Impact Leader & Co-Founder of the Malala Fund and Our Place

Peter Diamandis

Founder & Executive Chairman of the XPRIZE Foundation; Author; Named One of The World's 50 Greatest Leaders

Dom Sagolla

Co-Creator of Twitter; Author of "140 Characters"

Van Jones

CEO of REFORM Alliance, CNN host, Emmy Award-winning Producer & NY Times Best-Selling Author

Erin Brockovich

Consumer Advocate, Author, TV Host & Environmental Activist

America Ferrera

Award-Winning Actress, Producer & Humanitarian

Simon Sinek

World-Renowned Leadership Expert & Best-Selling Author

Lisa Ling

Award-Winning Journalist & Producer for CBS News

Erin Gruwell

Founder & Executive Director of the Freedom Writers Foundation; Education Reform Advocate

Antwone Fisher

Best-Selling Author, Screenwriter & Lecturer

Chris Sacca

Google & Twitter Innovation Guru

Bill Nye

"The Science Guy"; Science Communicator, TV Presenter & Mechanical Engineer; Climate Change Activist

Ben Stein

Political Economist, Commentator, Author & Actor

Marilyn Tam

Leadership Speaker, Bestselling Author, Consultant & Board Certified Corporate Coach; CEO of Marilyn Tam & Co.; Founder and Executive Director of Us Foundation

B.J. Novak

Actor, Writer & Comedian Known for "The Office"

Sophia Bush

Actress, Humanitarian & Author

Mayim Bialik

Neuroscientist, Host of Jeopardy!, Mental Health Advocate & Actress Known for "The Big Bang Theory"

Mayim Bialik on Why She Started Talking About Her Mental Health

George Takei

Actor, Social Justice Activist & Social Media Mega-Power

Soleil Moon Frye

Social Media Expert, Entrepreneur & Eco-Leader; Author of "Happy Chaos"; Alzheimer's Awareness Advocate

Chris Hardwick

Creator of Nerdist Podcast and Website, Stand up Comedian and Current Host of "The Walking Dead" after show, "Talking Dead"