Nos. 22-23: Will Pearson, Mangesh Hattikudur

Ages: both 28

Location: Birmingham, Ala.

Employees: 12

2006 revenue: $1.7 million

Year founded: 2001

Mental Floss magazine offers an irreverent look at knowledge and facts. As Pearson puts it, "Our mission is to find any way we can to blur the lines between education and entertainment." The founders started the venture at Duke University as a campus publication and quickly turned it into a national magazine. And they have pushed the brand further than the magazine, producing books, board games and, soon, a series of children's books.

• Go back to No. 21

• Go to Nos. 24-25

• Return to the full list

Source: Inc.com

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