You have your appointment time at the embassy. You turn up and they call you to the desk and you hand over your docs. You then go and sit down for about 4 hrs before they call you back. The lady then says, "watcha dooing in the USA" and you tell he, and she goes "cool, you'll have your passport back in 2 days"....
That's my experience too. Only in my case it took three hours instead of four. I wish I had brought a book or something, and maybe a bottle of water. And the answer to the single question that they asked me was "Cessna's".
One other thing to note: The photo you have to hand in (which becomes part of your visa) has to conform to the US size rules. Standard European passport photos are NOT accepted. When I was there almost half of the applicants were turned away because they had the wrong photo format. They were nice enough to hand out the business card of a nearby camera shop who could do the photos in the proper format though.