HongKong is fun and all, but after three/four days it might get boring.
Check prices for the flight on the internet. I think that is the best way.
If you let us know how long you stay and what you have planned, then I might have some better suggestions.
Some Tips:
- Don't change money at the airport. Bad rates. Change it at a bank, or when that is too much of a hassle, go to the Ferry Station in Kowloon and change it there. The rates there are much better.
- Buy a return ticket for the Airport Express! Will save you money!
- HongKong is THE place to buy shit. Especially Electronics. You just gotta be prepared. Check prices in the States before you go in there. I always go to the little Electronic shops in Kowloon. Those guys know to take your money with you leaving, thinking you got a good deal. So, be prepared and you'll get a good deal.
- If you want to smoke weed, the Pakistani/Indian dudes normally sell hash. They might just ask you to buy Gucci Bags etc., but they also got that connect.
- Don't go to Disneyland. Ocean World is also not the best theme park...
- Like Live said, hit up Macau if you are into gambling. You can take a ferry. They got the biggest Casino in the world there. I've never been there though.
- Try to go to a local restaurant with a local. At least once you have to try real HongKong/Guangdong food.
- If you got more time, take a trip to Xiamen which is close by and I show you this part of China!