GPS navigation systems are available in South Korea. Actually, GPS navigation is a must have if you are driving a car in South Korea!
The signs are in Korean (Hangul) but also in English. But it's much more convenient if you don't have to worry about the driving directions.
You don't have to get lost anymore.
The GPS maps are also in English too. And it's even English spoken. You can buy software for your mobile phone, PocketPc (PPC), Blackberry or smartphone. But check first at the manufacture if your device supports GPS and the Korean map
It must have a GPS devie like TyTNII, HTC Touch Pro, HTC Touch Diamand and a couple of Nokia phones (N95, N96, E90).
It's difficult to buy a map before you departure. Even at Google maps you wont find the map of Korea!