Learn to speak Korean. The Korean alphabet is not hard to learn, and once you have it down you will impress the locals with your knowledge
My professor went over to Korea for his mission (LDS) and he absolutely loved it. He speaks Korean extremely well now. I wish i could go, I think it would be an absolutely awesome experience.
Stuff is pretty cheap over there as well. Just beware of what you say, the Korean language has several levels of respect, three of them are most common.
hashimnika - Anyounghashimnika - Hello good sir:
Used when addressing someone that is older than you, or someone you hold in high regard.
hashjeo - Anyounghashjeo - Hello
Used when you know the person you are talking to, and you are friends. Will also be used by people who you would address with the above, especially if they are older. It will seem rude, but at the same time it is just acknowledging that since they are old they have the right to just say it.
pan mal - Anyoung - Hello.
This is named pan mal, this is the lowest you can go, and has two succinct different meanings. If you are speaking to someone on the street who you do not know, and you use this you are extremely disrespectful, and you will get yourself in a fight. However it is also used to show extreme affection/love and closeness. Between husband and wife pan mal may be used, between brothers and sisters pan mal may be used. Parents will also generally pan mal their kids.
To most foreigners it is a funny concept, that what is considered very disrespectful is also considered to show closeness, and a relationship. Just beware that using the wrong level might cause problems. Other things to keep in mind, Koreans do not have much personal space, and as such it is not uncommon for them to stand very close to each other. Americans especially like their own little circle, a bubble, you won't have that there. Also, my professor is pretty hairy on his arms, this is uncommon to see on Korean males, at one point he had a lady on the bus rubbing his arm because it was hairy. This is not considered rude.
One more thing about the Korean people. They will tell you the facts straight up. For example, when I went to the Korean market here in Phoenix the owner straight up said I was tall and fat. Most people would be offended but he was just offering an observation. No circling around it, just straight go for it!
Oh, while you are there, send me back something
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Kamsamnida.