Here are some quotes that Jeff Harrow of The Harrow Group found:

“If I were just setting out today to make that drive to the West Coast to start a new business, I would be looking at biotechnology and nanotechnology.”

 Jeff Bezos, founder of Amazon.com
 From the May 14, 2004 Nanotech Insider
 http://www.forbesinc.com/newsletters/nanotech/

Michael Dell [answered] “nanotechnology,” when asked by an MIT student which areas he’d focus on if he had to start his career today, all over again.
From the May 14, 2004 Nanotech Insider

Another good addition may be: “Look at both, since they will likely converge in NBIC applications within a few years. NBIC stands for Nano, Bio, Info, and Cognitive Sciences – the intersection of nano-scale, life sciences, info science (for tracking what’s happening), and cognitive sciences (for building smart systems.)