4. Malcolm Gladwell

Social Scientist and Author

"In order to get one of the greatest inventions of the modern age, in other words, we thought we needed the solitary genius. But if Alexander Graham Bell had fallen into the Grand River and drowned that day back in Brantford, the world would still have had the telephone, the only difference being that the telephone company would have been nicknamed Ma Gray, not Ma Bell."

5. Marissa Mayer

VP, Google

"The Googly thing is to launch products early on Google Labs and then iterate, learning what the market wants — and making it great.' The beauty of experimenting in this way is that you never get too far from what the market wants. The market pulls you back."

6. Sheryl Sandberg

COO, Facebook

"What Mark worries about the most is the lack of change, the lack of innovation, becoming the innovator's dilemma company that gets big and stops moving and stops staying ahead."