"If I had to nail one thing that has been consistently different, it's that as a consultant CIO, they actually listen to you," Arriaga says. "There is something in the minds of the execs and people I help that creates an openness to listening to the recommendations I'm bringing to the table. I've enjoyed that creativity the most."

When Phil Farr opened his consultancy, Dallas-based Farr Systems, in 2006, he drew upon four years of experience as a CIO at security firm Brink's and 11 years as director of IT at the former Fina Oil and Chemical Co. Immediately after leaving Brink's, Farr, 65, ran a food company for three years and then became a CIO consultant with the Tatum professional services firm in Dallas before heading out on his own.

So why did he leave his role as a CIO?

One reason was the toll of travel. "I traveled in 54 countries for Brink's and throughout Europe for Fina," he says, whereas most of the work he does now is local or at least U.S.-based.

Beyond that, "my ambition was to be a businessperson who could run IT or any other needed part of a business," Farr says.