I asked Darryl Johnson how he came to be in the foreign service, ambassador to 3 countries and more (see his info on Classmates on the Web). He smiled and said "I took the exam". He said he didn't have any job plans and a friend suggested he take the foreign service exam, so he signed up. He had some doubts while taking it, as it was the hardest exam he had ever taken, and there was a football game that day. He passed, and also passed the oral exam some weeks later, and was assigned to an embassy in India. It was small, only 8 personnel, so he got more than the usual diversity in his work, and the rest you can see on the Web. The reported speeches are good too. I will have to ask him if he wrote his own material.