Speaking Korean is not a prerequisite for teaching English in Korea. Some people pick it up after they live there, bring a phrases book, or take classes once they realize how tough living in a country where they don't speak the language is. From what I gather, the children I'll be teaching might be the only translators available. But I am going to live there for a year and have no desire to feel helpless, lost, and afraid of what's on the menu every time I'm hungry.
So I found this spiffy Web site, Livemocha.com, which offers free language lessons and is also a social networking site so you can get help from native speakers and offer assistance to others. It offers writing, reading, and speaking lessons. I now know FIVE whole words of Korean (man, woman, girl, boy, and hello) and can almost write them, too. Learning a new language is easy until you add in the completely new alphabet. It takes two symbols to express single words. Yikes. I can't wait to learn how not to order fish in Korean! Check it out and add me; my username is themonbelly.
***As of December 2009, Livemocha hasn't helped me learn shit as far as Korean goes. It's very helpful for learning Spanish and brushing up on my French, though. I prefer this site for learning the alphabet and have been taking free lessons near the Sookmyung Women's University station Saturdays 4-5:30.***