HSBC has one of the largest networks and best online banking system.
Needless to say if your North American bank has a branch in Hong Kong, you might want to use them also.
HSBC used to have a debit Visa, but it failed. You can use your ATM card at most locations using a service called EPS.
http://www.eps.com.hk/
You can also pay bills at over 1500 merchants using your phone or browser using
http://www.ppshk.com/
Finally the Octopus stored value card can be used for a large number micropayments (< $100 HK) at places like 7-11 etc.
http://www.octopuscards.com/eng/index.jsp
You'll find Hong Kong to be far more advanced than the United States or Europe when it comes to finding easy ways to take your money.
