Usually after a night out in Hongdae (Seoul's club district) Hannah Teacher wakes up with a pretty brutal hangover. Blame it on the Soju...
The past 3 months I have come to realize that drinking is a major part of the Korean lifestyle. You can drink anywhere in the city. On the weekends, you usually see people stumbling around as early as 10PM. Sometimes, if you're lucky, you will see people randomly passed out everywhere; on the subway, in restaurants and even on the sidewalk. There is even a highly entertaining website dedicated to this issue (http://blackoutkorea.blogspot.com/).
Soju is native to Korea. It is typically made from rice. It is a clear liquid and ranges from 20-40% alcohol by volume. You can find Soju anywhere, and it will cost you less than ₩ 4,000 (around 3-4 dollars). Koreans usually just drink it straight in a shot glass alongside their kimchi and bbq, but I prefer it mixed with Powerade. Another popular way to drink it is shot by shot, mixed with Dr. Pepper. "Soju Kettles" are popular at some bars, which consists of kool-aid and Soju served in a plastic bottle with the top cut off.
If you're looking to hop on the train to black out city, Soju is the drink for you. The stuff always seems like a good idea at the time, but one always regrets it in the morning (trust me). I don't know how the Koreans do it. Cheers to them.