Tebs, Its very quick. From the day I sent in all the forms to the day Martin got his visa in hand (interview day) it was 85 days. So just under 3 months. Not bad eh?
Trish, I dont know the answer to your question either. Not for sure anyway. Generally the interview is done at the US Embassy, consulate, or overseas mission that has jurisdiction over the area in which you premanently reside. I have heard cases where the paperwork was filed at one US Embassy and the interview took place at another. For instance, people permanently residing in India but working in the UK could file in India and attend their interview in London. My best advice is to email the US Embassy that covers your area.
Best wishes,
Sarah