Do keep in mind that Korea will be quite cold in the winter. One thing I have always wanted to do is take a bus tour of the DMZ between North & South Korea. Apparently, the tours are relatively inexpensive and do not take terribly long (<5 hrs, IIRC). From what I read in a travel magazine, its a one-of-a-kind experience - right down to seeing the "typical North Korean city" which was mocked-up right across the border.