The best way to get around in Hong Kong is by train, buses and of course by foot. Hong Kong has a great and modern subway system (MTR). For getting around I highly recommend you to buy an “Octopus Card” (a prepaid travel card). You can get it at the airport or any MTR station.
The card costs 150HKD and its preloaded with 100HKD for use and 50HKD refundable deposit. The card is accepted by over a 1000+ merchants which includes public transport (MTR, Bus, Tram, Ferry) and 7-eleven, McDonald’s, Starbucks and many more.
You also enjoy discounts with some merchants for example MTR.
Using the card is very easy and convenient. Once you get it, just put it in one of the card slots in your wallet and you never have to take it out again for paying. Just place your wallet with the side of the card close to the reader and that’s it.
On the MTR gates it is on top of the access gates to the paid area with the Octopus Card logo.
You can recharge your card at any MTR station at the customer service desk.
More info at http://www.octopus.com.hk