Web 2.0 second acts

Web 2.0 (or Bubble 2.0, as critics see it) has serial entrepreneurs buzzing with plans for a fresh hit. Will they fly high or get zapped?

•  The Twitter trend  

Sarah Lacy addresses that question in her new book, Once You're Lucky, Twice You're Good, as she untangles connections among Digg, Facebook, Twitter, YouTube, and others; and Marc Andreessen (Netscape), Jay Adelson (Equinix), and Max Levchin and Peter Thiel (PayPal).

"I wanted to find their core motivator," Lacy says: "What made them go through all the pain and heartache again when the late '90s were so brutalizing?" She uncovered their biggest lessons: Keep control of your company, and be wary of venture capitalists.

Entrepreneurs from New York City's Silicon Alley are also launching Web 2.0 second acts. Click through for our scorecard.