Dim Sum Bar & Restaurant - 620 O'Farrel St.
Sushi Aka Tombo - 1737 Buchanan St.
Sally's Famous Fishwich - Pier 43 1/2, Fisherman's Warf; I don't recommend anything else on or near Fisherman's Warf.
City Lights Booksellers & Publishers - 261 Columbus Avenue
There's an excellent, smaller bookstore I visited staffed by a nice young lady and a grumpy old hippie. I think it's Adobe Book Shop on 3166 16th St. but I can't recall for sure.
I thought the Castro was underwhelming. I expected it to be gayer. Union Square has some good shopping, and it's all located inside of Barney's - Saks and the other menswear shops weren't very compelling to me when I visited.