The Free Thinker: Caterina Fake of Hunch

In a country whose citizens work longer and get more done than those anywhere else, no one is more productive than entrepreneurs. They have unparalleled freedom to work the way they want, and many create truly personal productivity systems to lash their to-do (and do and do and do) lists into submission. Like the companies themselves, those systems reflect the CEOs' values, goals, and leadership styles. To get a look inside the minds of the superefficient, Inc. interviewed successful entrepreneurs in various industries around the country. (For more, see Inc.com/personal-productivity.)

• The Chief Recruiter: Kevin P. Ryan, AlleyCorp: Ryan's encore to DoubleClick—the ad-serving behemoth he sold for $1.1 billion to private equity firm Hellman&Friedman in 2005—is AlleyCorp, a variety pack of Internet start-ups he founded in New York City.

• The Engager: Seth Priebatsch, SCVNGR: CEO of SCVNGR, a Boston-based start-up that helps organizations engage people through location-based smartphone games.

• The Space Maker: Scott Lang of Silver Spring Networks: CEO of Silver Spring Networks, a developer of smart energy grids, based in Redwood City, California.

• The Alphebetizer: Barbara Corcoran, Barbara Corcoran Inc.: Corcoran made her mark building one of New York's largest real estate companies. Today, she is a panelist on the ABC program Shark Tank and runs a much smaller firm that works with the start-ups she chooses to invest in on that show.

• The Gracious Host: Danny Meyer, Union Square Hospitality Group: CEO of Union Square Hospitality Group, which owns 13 New York city restaurants, including Gramercy Tavern and Eleven Madison Park.

• The Modern Homemaker: Rocio Romero: Rocio Romero founded her namesake firm which manufactures prefab modern homes.

• The Iron Man: Jordan Zimmerman, Zimmerman Advertising: Founder of Zimmerman Advertising, which has 22 offices and billings in excess of $2.6 billion.

• The E-Mail Zealot: Mark Cuban, Dallas Mavericks: Owner of the Dallas Mavericks who has been launching, buying and selling companies for a quarter of a century.

• The Shortcut King: Charles Best

• The Free Thinker: Caterina Fake, Hunch: Co-founder of the photo-sharing site Flickr. Her new start-up is Hunch, a website in New York City that takes user input to make recommendations on thousands of subjects.

• The Cage Dweller: Karl Hoagland, Larkspur Hotels: Founder of Larkspur Hotels and Restaurants, in Larkspur, California.  It recorded $20 million in sales in 2009.

• 3 Tips for Super Productive CEOs: Advice from Garrett Camp of StumbleUpon, Krissi Barr of Barr Corporate Success, and Julie Ruvolo of Solvate.

• Case for a Cluttered Inbox: How to Compartmentalize: In his new book, Getting Organized in the Google Era, former Google CIO Douglas C. Merrill discusses ways to maintain order in an age of information overload.