Use Naver Maps offline on your iPod Touch / etc.

Problem:
You don't want to be lost around Seoul, or anywhere in Korea for that matter, but you don't have a smartphone. You do have an iPod Touch (or iPhone) or other wifi-only device, but what if no wifi signal is available?

Solution:
Use the offline cache feature of Naver Maps. Here's how:

Download the Naver Maps app at the Apple App Store or Android Market
(this tutorial uses the Android version)

1. Press the Menu button
2. Select the 저장 ("Storage") button on the bottom-left
3. A pop-up menu appears, with two options: 지도 저장 (Save Map Info) and 저장 목록보기 (View Stored Map)
4. Choose 지도 저장
5. The map appears with a centered circle. That circle will be the downloaded map area. Choose the size of the area you want saved (250m, 500m, 750m, 1km, or 3km)
6. Click 완료 (Done).
7. Wait as the app downloads the map data
8. A confirmation will pop-up when complete. Choose 듣기 (Done)

To view your cached map data offline, repeat steps 1-3, but choose 저장 목록보기 to view a list of your saved maps. Note that you can save multiple map areas (I like to keep offline map areas of my local area as well as of Itaewon / Hongdae / central Seoul, just in case...)

You can use GPS or wifi-location-matching to find your current location on your downloaded map. You can zoom in/out as usual. Note, however, that you will be unable to search or get transit directions.

EDIT 2012-06:

The interface is slightly different now. New instructions are:

1. Press the Menu button
2. Select the 다운로드 ("Download") button on the bottom-center
3. A pop-up menu appears, with two options: 내 기기에 지도 다운로드하기 (Download Map to my Device) and 다운로드한 지도 목록보기  (View Downloaded Map List)
4. Choose 내 기기에 지도 다운로드하기
5. The map appears with a centered circle. That circle will be the downloaded map area. Choose the size of the area you want saved (250m, 500m, 750m, 1km, or 3km)
6. Click the download icon (arrow pointing downward).
7. Wait as the app downloads the map data
8. When 100% is reached, Choose 완료 (OK)