Some of these have included:

Authors

• The late author of The Hitchhiker's Guide to the Galaxy Douglas Adams
• Geneticist and author Steve Jones
• Writer, lecturer and broadcaster Dr Susan Blackmore
• Australia best-selling author, science fiction’s Matthew Riley

Astronauts

• America's first female astronaut Sally Ride
• NASA's Franklin Chang-Diaz

Comedians

• Tom Gleeson
• The Good News Week team and special guests
• The How Green Is My Cactus radio team

Creativity specialists

• Author of The Creative Economy John Howkins
• Author and creative planning adviser to governments around the world Charles Landry
• Pioneer on the knowledge economy Kate Oakley

Entrepreneurs

• Vacuum cleaner baron James Dyson
• IBM Corporation’s Vice President, Market Development, Marilyn Johnson
• Freedom Furniture co-founder and Fantastic Furniture MD Julian Tertini
• Murrays Travel Ron Murray
• Real estate's John McGrath, Richard Luton and Vicki Laing
• MD Pinctada Hotels & Resorts, actress and Director of Paspaley Pearls Marilynne Paspaley, AM
• Louise Curtis, Director HamperEsque and Lollypotz
• Ruth Med, Chair, Women on Boards
• Property developer John Hindmarsh
• Event organiser Suzi Dafnis
• Roses Only's James Stevens
• Powercom MD and Novaris GM Diane Thompson
• Australian Research Council CEO Professor Margaret Sheil

Environmentalists

• Sir David Bellamy
• Harry Butler
• Photographer Steve Parish
• Bush Tucker Man Les Hiddens

Inventors

• Inventor of the Triton Workbench George Lewin
• Maternity belt inventor and journalist Christine Kininmonth
• Inventor of the dripless teapot Damini Kumar

Journalists and presenters

• Top Gear’s Warren Brown
• ABC presenters such as Phillip Adams, Robyn Williams, Julie McCrossin, Paul Barclay, Richard Aedy, Sandy McCutcheon, Maxine McKew, Ross Solly, Bernie Hobbs, Paul Willis, Dr Norman Swan, Alan Saunders, Chris Uhlmann, Louise Maher and Alex Sloan
• New Scientist Editor Alun Anderson
• The New Inventors' James O'Loughlin
• The Australian's Peter Switzer and Asa Wahlquist
• Journalist Helen Daley and Computing commentator MS Megabyte
• Boss Magazine editor Narelle Hooper

Politicians

• Ranging from ACT Chief Ministers and Governors-General to Australian Science and Environment Ministers

Science communicators

• IVF pioneer Lord Robert Winston
• Britain's then Chief Scientist Sir Robert May and Australia's former Chief Scientist Dr Robin Batterham
• Director of Britain's Royal Institution Baroness Susan Greenfield
• Time magazine's first Hero of the Planet marine biologist Dr Sylvia Earle
• Neurologist Professor Colin Blakemore
• Dr Karl Kruszelnicki and Adam Spencer
• Deane Hutton and Rob Morrison from the Curiosity Show
• Mathematician and Ig Nobel founder Marc Abrahams

Thinkers

• The man who coined the term "lateral thinking" Edward DeBono
• Nobel Prize winner Peter Doherty