The United States currently has the greatest number of centenarians in the world, estimated at 70,490 on September 1, 2010. (Article on centenarians on Wikipedia.)
And, although it is not proven, it is not unreasonable to think that talking to centenarians and reading about them could trigger more willingness and desire to live to 100.
Want to join this list? List of the verified oldest people.
Meet the world’s oldest living person, Maria Gomes Valentim