Fortunately, the island is connected to the rest of the city by tunnels running under the harbor where trains and buses can pass through. The trains themselves are also quite new and clean. Unlike New York, eating and drinking on the train and bus is prohibited and can carry heavy fines. (I oddly miss the rush of eating a bagel on the train on the way to an internship in Manhattan.) They also stop running during the night, which can be a bit of an inconvenience.
The city also hosts a number of unusual transit options. The Star Ferry is one of them and is made up of old ferry boats that take about 10 minutes to cross the harbor. It is slow but the system is amazingly cheap (less than $1.00) and offers some of the best views of Hong Kong. There are also mini-buses that zip across the city's less densely populated areas. Since most of these drivers are used to the hilly roads, they make sharp turns and can sometimes feel like a roller coaster ride! And lastly, there are electric tram cars that date back to 1902. Locals call them "Ding-ding" after the sound they make when crisscrossing Hong Kong Island.
In all honesty, I am a bit jealous of how nice public transportation is here in Hong Kong. One thing that I have noticed however is that the trains can sometimes get even more crowded than the ones in New York during rush hour! In fact, I was quite shocked to see how frequently the trains run, yet how crowded the trains still manage to get. I think it is one of the things that still surprises me about being in China -- crowds are something you just have to get used to!