I once went to a US Department of State open meeting for potential Foreign Service Officers. It was a very interesting presentation, but I decided it wasn't for me. I'm just not that into economics, international policy management and whatnot. (Of the five tracks, I rated highest in public diplomacy followed by management/admin).
They scared us with stories of being airlifted from the roof of an embassy during some crisis - one guy said it happend to him twice.
They were very clear in mentioning that the exam is not easy and that *if* you pass, you'll be added to a waiting list of candidates.
Overall though, I could tell that they really liked what they did and had some exciting times.
It sounds like you've got the "go get 'em" attitude! Rock that test, Rudey!
.....Kelly