What books are on your "must read" list for web startups?

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The Innovator’s Dilemma & The Innovator’s Solution by Clayton M. Christensen
The Entrepreneur's Guide to Customer Development: A Cheat Sheet to the Four Steps to the Epiphany (Brant Cooper209 , Patrick Vlaskovits210)
Business Model Development: A Handbook for Visionaries, Game Changers and Challengers (Yves Pigneur and Alex Osterwalder)
Crossing the Chasm: Marketing and Selling High-Tech Products to Mainstream Customers
Inside the Tornado: Marketing Strategies from Silicon Valley’s Cutting Edge
Founders at Work (Jessica Livingston201)
Dealing with Darwin : How Great Companies Innovate at Every Phase of Their Evolution — all three by Geoffrey A. Moore
Escape from Cubicle Nation: From Corporate Prisoner to Thriving Entrepreneur (Pamela Slim)
The Tipping Point: How Little Things Can Make a Big Difference by Malcolm Gladwell
Blue Ocean Strategy: How to Create Uncontested Market Space and Make Competition Irrelevant by R. Mauborgne and W. C. Kim
Business Model Generation: by Alexander Osterwalder