Acknowledgments This book is for Boris and Lydia Kuniavsky, my parents, who bought me a Com- modore PET 2001 when they barely understood what it did, and who have expressed unwavering support for every crazy thing I have ever tried. It is for my grandmother, Feodosia Sheinker, a lifelong journalist who encour- aged me to write this book. She would have turned 100 this year. It would not exist if not for the support, encyclopedic knowledge, fantastic insight, blisteringly fast editing skills, and--mostly--love and patience of my wife, Elizabeth S. Goodman. It is for her, and it already is hers. I am in intellectual and social debt to: Adam Greenfield, Andrew Otwell, Ben Cerveny, Bill Buxton, David Zicarelli, Eric von Hippel, Erika and Mike at Mule Design, Genevieve Bell, Jan Borchers, Jeff Callahan, Jesse James Garrett, Judith Zissman, Malcolm McCullough, Matt Cottam, Matt Jones, Matthias Richter, Susanne Backer, Molly Wright Steenson, Ruth and Erez Kikin-Gil, Ryan Scott Bardsley, Souris Hong-Porretta, the MIT Media Lab, the participants of Sketch- ing in Hardware, the students and staff of Interaction Ivrea, Timo Arnall, Tom