Like all large tourist cities, Hong Kong has many tour operators ready to show you around town. This could be a good idea if heat is a problem for you, and the tour offers air conditioning. The tours are also great if you don't want to bother reading tour books or information plaques. They are however not cheap, and it can be a challenge finding a tour that suits your interests. I personally found the number of tours of Hong Kong to be vastly overwhelming.
The problem is, how can you see the city, and also get around in a fun way above the ground. If getting around is all you need the metro system is pretty good, and only a little pricey. If you want to make your trip a little more fun, there are a few options that will take you around, give you great views, and all for far less than any tour.
On Hong Kong island, the most fun you'll have getting around is on one of the double decker trams. They're basically a cross between a double decker bus and a streetcar. There are several routes to chose from, and many stops at several popular tourist spots. It might take a bit to figure out how the stops work, but a little research online and you should be fine. The first thing you should know is that it's best to know what number your stop is, each stop is fairly well marked, and the numbers are in order. Secondly make sure you have correct change, and pay when you get off. Other than that, try and get a seat on the top front, and enjoy watching the city pass by.
Another cheaper alternative to a tour is the Star Ferry. Hong Kong offers many boat tours of the channel between Kowloon and Hong Kong Island, but for only a few bucks you can take the ferry across, and still enjoy these awesome views. Although the announcement suggests that you remain seated, I never once saw this rule enforced. There are some great photo opportunities from this boat, and you won't break the bank either.
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