Over the years, over the eight editions of this book, many friends and colleagues have contributed enthusiasm, expertise, and even prose to its editions. They include Zachary Brass, Dan Pourhadi, Rich Koster, J.D. Biersdorfer, Teresa Noelle Roberts, and Lesa Snider.

In addition to the dream team identified above, I owe debts of thanks to O’Reilly’s Missing Manuals editor-in-chief, Brian Sawyer; Apple’s Ryan James for going beyond the call of duty to chase down tweaky tech answers; Philip Michaels, who wrote about Game Center for this book; my crack team of eleventh-hour proofreaders, Kellee Katagi, Judy Le, and Nancy Young; and my assistant Jan Carpenter, who makes my very survival possible.

I’ve never met, or even spoken to, Kirill Voronin; he lives in Moscow. But he submitted so many corrections to the previous edition’s Errata page online that I wound up hiring him to be the tech editor for this book—and he knocked it out of the park.

I also wish I could send out an “I Made the Book Better!” T-shirt to every reader who ever took the time to write with corrections, suggestions, tips, and tricks. And thanks, as always, to David Rogelberg for believing in the idea.

Above all, this book owes its existence to the patience and affection of Nicki, Kelly, Tia, and Jeffrey. They make these books—and everything else—possible.

—David Pogue