Brad Pitt and Angelina Jolie are influential.

The pair ranked No. 21 on TIMES's 2008 list of the world's 100 most influential people.

In an article written by George Clooney, the actor writes, "It is one thing to talk about the problems of the world and quite another to actually try to change things."

"they have tended to the poor and sick in Africa" and how they shelled out $1 million for the victims in Darfur, among other humanitarian efforts.

Says Clooney, "The couple cares for three adopted children , from Cambodia, Ethiopia and Vietnam, in addition to their biological daughter.

"There are hundreds of people who could be honored for their good works, but I've seen Brad and Angelina firsthand, and their commitment together is truly impressive," he adds.

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