My wife and I will be coming to SF from Seattle to meet a young Korean couple on their way to ASU where he will begin working on his PhD. This will be their first visit to the US. I can't think of a more exciting introduction to America than a few days in SF, but because we haven't visited in over a decade I would really appreciate some suggestions. We'll be staying in the downtown area, probably near Union Square, and will be either hoofing it or using public transportation. Food budget will be moderate but not low, casual lunches and dinners, maybe one 'big' dinner ("big' more in view or ambiance than culinary). 'Touristy' suggestions are welcome; we cooked cioppino for them when we were in Seoul last summer and it would be fun to compare our effort with the real thing - still available from vendors on Fisherman's Wharf? We'll probably be strolling Fisherman's Wharf, North Beach, Union Square, Marina, Castro, plus open to other suggestions. When in Seoul they took us to a B-Boy Show and we'll reciptocate with Beach Blanket Babylon. So: downtown area, no car, moderate price, uniquely SF. Any and all suggestions will be greatly appreciated! Thank you.