How long does it take to get my Visa?

Generally, you can complete the procedure on the same day but get your visa in 4 working days. If in a hurry, you can use express/same day processing service which takes 1-3 working days at additional cost.

Does this mean that I will have to again fly down to San Francisco to pick up my visa?

I'm not very sure about how things are going on in San Francisco consulate. But in Los Angeles consulate, people can entrust someone else to pick up the visa on their behalf and then have it delivered to their place.

BTW, some feedbacks indicate it takes more days than before for the processing because of increasing applications. Anyway, after lodging the submission, you will get a receipt telling on which day you can pick up your visa.