From Author Website

From Wikipedia

Joi Ito

MDCarchives

Courtesy of the NYPL Digital Gallery (image use requires permission from the New York Public Library)

Courtesy of the Perry-Castañeda Library, University of Texas at Austin.

Courtesy of Allen and Unwin

"With Light from a New Dawn", painting by Eric Robert Morse, 2005, depicting Jacques Barzun in profile at around the age of 40

Library of Congress/Wikipedia

Courtesy of Hay House, Inc.

Katherine Young, Library of Congress

Photo by Yousuf Karsh, Dec. 30, 1941, Ottawa, Ont.
(Yousuf Karsh / Library and Archives Canada / PA-165806)

Derrick Coetzee
Building 17 on Microsoft's campus in Redmond, Washington, USA

Mathematisches Forschungsinstitut Oberwolfach, http://owpdb.mfo.de/detail?photoID=726

Photo courtesy the University of Chicago Experts Exchange (link)

Courtesy of the NYPL Digital Gallery (image use requires permission from the New York Public Library)

Wikipedia author Markus Pössel (Mapos)

Matti À (Reykjavik, 2006).

Daniel C. Dennett

Julian Cash

Quiz show "21" host Jack Barry turns toward contestant Charles Van Doren as fellow contestant Vivienne Nearing looks on/photo by Orlando Fernandez: New York World-Telegram and the Sun Newspaper Photograph Collection (Library of Congress)(LC-USZ62-126813)

"Portrait of the Writer Fyodor Dostoyevsky",
Oil on canvas.
The Tretyakov Gallery, Moscow

Photo by James Duncan Davidson/O'Reilly Media, Inc.

from Wikipedia

Receiving an honorary degree at the
Università Mediterranea di Reggio Calabria, 2005
(credit: Università Mediterranea di Reggio Calabria)

Photo by Yousuf Karsh, 1948
(Yousuf Karsh / Library and Archives Canada / PA-212510)

Rick Stafford

Wartime Los Alamos badge photo

Wartime Los Alamos badge photo

Credit: David Shankbone, 2006, New York City

Benjamin Franklin, by Jean-Baptiste Greuze, 1777

Charles Haynes

Used by permission: Victoria University, E.J. Pratt Library

Photo © Esther Dyson

photo by Sarah Harlin

Copyright Eye On Books.

Portrait by Daniel Huntington, based on John Trumbull. Via Wikimedia Commons

from Wikipedia

From the Marxists Internet Archive.

from Wikipedia

from Wikipedia

Peter Lauth / World Economic Forum

University of Chicago Library, Special Collections Research Center

Crop from bigger picture. Taken by Päivi Kuusjärvi, Helsinki Beer Festival, April 2004.

From the Marxists Internet Archive.

Photo courtesy the University of Chicago Experts Exchange (link)

By permission of Brian Kernighan

Photo © Esther Dyson

from Wikipedia

Wikipédia France

wikipedia

U.S. Naval Historical Center

http://www.useit.com/jakob/photos/

James Duncan Davidson

Photo courtesy of Hay House, Inc.

Jerry Bauer

ensceptico

Hatchette Book Group USA

New York World-Telegram and the Sun Newspaper Photograph Collection, Library of Congress, Prints and Photographs Division, Reproduction Number LC-USZ62-114904

Photo credit: Russ Nelson , June 3, 2005

© 2005 Matt Ridley

Maurice-Quentin La Tour (1704-1788)

Wikipedia

Courtesy of the NYPL Digital Gallery (image use requires permission from the New York Public Library)

Photo by David Shankbone,
Strand Book Store, New York City,
Aug. 15, 2006

Flickr user Joi

From Wikipedia

Wikipedia

By James Duncan Davidson/O'Reilly Media, at OSCON 2006.

Bundesarchiv, Bild 183-R06610, Fotograf: o.Ang.

from Wikipedia

Taken by Stewart's wife, Avril Stewart.

Keenan Pepper

public domain

Flickr user fortdrastic (2005).

Wikipedia: "Publius Vergilius Maro" Description: Bust of Vergil Date: April, 2005 Author: A. Hunter Wright

From Wikimedia Commons

Photo/copyright: Sue Adler

Photographed at BookPeople in Austin, Texas by Frank R. Arnold

Photographer unknown. From the Dibner Library of the History of Science and Technology

This image was made in 1887 in New York, by photographer George C. Cox (Wikipedia)

J.D. Sloan

Ben Stechshulte