hehe Hong Kong...
ummm... where should i start??
if you'd like to do exquisit shopping, i would say, go for Tsim sa Tsui and Central.
Causeway Bay is good in terms of both exquisit and bargain hunting.
but definitely go to Mongkok to do some bargain hunting (temple street or Ladies Market they are both good!!!) but i wondered if your stay will be too short to go around?? if you're heading straight from the airport, i would suggest... take the airport express to Central then change to Tsim Sa Tsui or Mongkok. that will take about 45 minutes... but airport ticket aint' cheap. otherwise you can always catch one of the airport buses (cheaper), or take S1 to Tung Chung then change to MTR.
if you just wanna get a little bit of it, there's an esprit outlet at Tung Chung, great bargain i have to say!! 5 minutes away from the airport... take the Bus S1, or S64.
also... if you REALLY want to... there's always Disneyland, it's like 15 minutes away from the airport i think.
i am living in HK at the moment btw, let me know what you would like to do, and i can give you more info
you can just withdraw from most ATM with the Cirrus or Maestro signs on (depends on your debit card) some shops do accept US dollars and aussie dollars but it depends. exchange rate is fluctuating betwee 5.6 and 5.7 at the moment.
btw, which airline are you flying with??