Recently I had my UK passport stolen and had to fly out to the USA 2 weeks later. I was in Botswana at the time of the theft so I really had pressure.
I was able to apply online for an appointment at the US Consulate General in Cape Town and initially it said the earliest appointment was 4 November. I needed to get it done way sooner than that. I phoned the US Consulate General later that day and was advised that the booking slots had changed and I could get to them on 31 October. First lesson to learn:
THE BOOKING SCHEDULES CHANGE SO YOU CAN ALWAYS REFRESH THE BOOKING APPOINTMENT AND HOPE FOR AN EARLIER TIME SLOT.
When I arrived at the US Consulate General on the day of my appointment, I wasn't able to park anywhere near the building, so I had to double up and park at the shopping complex. The security guards figured out where I was going by the large document folder under my arm and pointed me to a more remote parking area for US Consulate visitors. Second lesson learned:
GET TO THE CONSULATE GENERAL WITH AT LEAST FIFTEEN MINUTES TO SPARE BEFORE YOUR APPOINTMENT BECAUSE YOU ARE GOING TO HAVE TO PARK +-300m FROM THE BUILDING AND STILL NEED TO WALK THERE.
Upon arriving I saw a long queue of people and naturally proceeded to the back of the queue. My appointment was 10:15am and it was 10:05am. The guard asked what time my appointment was, and I said 10:15am and she pushed me to the front. Third lesson learned:
MAKE SURE YOU'RE ON TIME FOR YOUR APPOINTMENT. IF YOU'RE EARLY, IT DOESN'T SEEM TO WORK ON A FIRST-IN-FIRST-OUT BASIS, SO INFORM THE GUARD OF YOUR APPOINTMENT TIME.
Going through security, I had to surrender my phone and electronic devices.
When inside the main area for visa applications, it didn't take particularly long for me to get through. At the front, I was asked three questions (unlike those ahead of me who seemed to be on the phone for ages):
"Why am I going to the USA"
"What's the longest I've stayed in the USA before"
"Am I a British citizen"
I was awarded a visa thereafter. I had to surrender my SA passport and do some magic thumb prints while holding a phone but afterwards, I left for my car, feeling quite relieved. Much later in the day I realised they had not taken the passport photo that I had brought along. I panicked. No-one could tell me on any of the phone lines I called whether this was a problem or not. Eventually I figured out the answer. Lesson #4 & #5:
IF YOU APPLIED ONLINE FOR THE VISA APPOINTMENT AND UPLOADED A VALID PHOTOGRAPH THEY WILL USE THAT FOR THE VISA STAMP.
IF YOU WANT A PROMPT ANSWER, USE TWITTER - I GOT THE ANSWERS I NEEDED VERY QUICKLY.
The entire process started 31 October, and my document will be collected tomorrow 3 November. Pretty much two or three working days.
Of course, if anything I've said above costs you your visa, please don't blame me. This is my experience and your mileage may vary.