Jabro did an interesting spot of research in a recent visit to Hong Kong, being sure to check out the numerous centres of otaku culture there, as well as plenty of more general sights. It does not look as if anyone with an interest in such things will have any difficulty finding what they are after in Hong Kong, not that this can be said to be surprising in the least.
As expected of a Chinese market… Chicken feet.
Abundant doujinshi.
By all means see the rest; there isn’t a great deal which isn’t immediately comprehensible from the numerous photographs. Also see more general photographs here and here, and some particularly nice Hong Kong cityscapes here.
Holi shit that’s Sino Plaza! OAO
For a closer look on the otaku side of things, may I recommend an article by 0ne, on The FØØL’s Progress? Here: http://textfiend.net/zerohero/?p=547
I found it quite useful during my own trip to HK (for which I wrote a quick report on my blog, but it’s all in French).