There are a few places where you can get all, and when I say all I mean ALL gadgets, for your 3C products (computer, communication & consumer electronics). You can find them at the Golden Mall at Sham Shui Po, Mong Kong Computer Centre, Mong Kong Sim City, Wan Chai Computer Computer Mall, and Wan Chai 298, 188 Malls.
Of these malls, Sim City is one of the top ranked in terms of cleanliness, and ease of access. Unlike some other malls where you need to go out of the way in order to get there, this place is pretty easy to pass by, as it sits on a street one black away from Tung Choi Street, one of the busiest streets in Kowloon.
Be it external hard disks, usb 'fingers', all sorts of charging cables, sim card adapters (to make small cards functional on older phones), screen guards, self-learning tutorial books on computer softwares (even books for International Japanese language exam!), camera bags, straps, you name it, and you can probably find it here.
Although one might say the prices here ain't ask cheap as that in Sham Shui Po, but it is such a timesaver. In Golden at Sham Shui Po I often feel lost in the sea of gadgets but here, the displays are rather clear, and I can easily just grab and go with what I needed in 10 min.s.
The shop that I'd spend the most amount of time here is the book store. It carries many Taiwan or Mainland tutorial books, and saves my time from hunting them down at Book City at Shenzhen and other upstairs-bookstores too. read more