5. Dan Hesse, President & CEO, Sprint Nextel

What makes him powerful: Sprint appointed Embarq executive Dan Hesse as its new president and CEO in December of last year. Hesse replaced former Sprint CEO Gary Forsee, who stepped down from the helm in October amid criticism for his performance and the escalating problems at Sprint.  

Although Hesse's most recent job had been heading up wireline operator Embarq, he was no stranger to the wireless industry. He spent 23 years at AT&T, including serving as president and CEO of AT&T Wireless Services from 1997 to 2000.

During that time, he is credited for convincing senior AT&T management to support AT&T Wireless' Digital One Rate plan. This plan was the first in the wireless industry to bundle roaming and long distance fees into a flat-rate airtime package for consumers. Digital One Rate was a huge marketing success. Other nationwide operators copied the Digital One Rate plan, which caused demand for wireless services to skyrocket.

Hesse has certainly had his hands full trying to turn Sprint around. The operator has struggled with its 2005 merger with Nextel and has been losing iDEN customers at an alarming rate. It also has been under fire for what some consider a risky (and costly) move--deploying a nationwide mobile WiMAX network in its 2.5 GHz spectrum.

Shortly after his appointment, Hesse made some big changes at Sprint. He eliminated 4,000 jobs, reduced the number of distribution points, including 125 company-owned stores and consolidating Sprint's headquarters to Overland Park, Kan.  

Under Hesse's leadership, Sprint also introduced an unlimited rate plan called "Simply Everything" which provides unlimited voice, data, text, email, Web-surfing, Sprint TV, Sprint Music, GPS Navigation, Direct Connect and Group Connect for $99.99 a month.

Hesse also became the "face" of Sprint by becoming a pitchman for the company. He's been in two advertisements so far. In the most recent one, he explains how customers can have their phones configured for them at Sprint retail stores.

But Hesse's most powerful move to date may be the crafting of a complicated deal that will combine Sprint and Clearwire's WiMAX businesses and create a new company that will include a $3.2 billion investment from Intel, Google, Comcast, Time Warner Cable, Bright House Networks and Trilogy Equity Partners. This deal is supposed to close by year-end.

When Hesse was named the new CEO of Sprint, not everyone thought he was the best man for the job. But if he can pull off a turnaround at Sprint, I suspect his critics will be silenced and he will once again be making wireless history.

5. Dan Hesse, President & CEO, Sprint Nextel