The other thread is just about TSST Korea and Samsung OMS, a personal tour inside Samsung.
Not that detailed but there must be other threads, too.
http://www.danawa.co.kr (like PriceWatch)
http://www.enuri.co.kr (somewhat more like PriceGrabber)
http://www.auction.co.kr (an eBay-owned company)
http://www.kbench.com (THG of South Korea)
http://www.airport.or.kr (Inchon International Airport, airport for Seoul)
http://www.worldwise.co.kr (Lite-On distributor)
http://www.okcdr.co.kr (Taiyo Yuden distributor)
http://www.bestcdr.net (Ritek distributor)
http://www.8hogongcd.co.kr (imports some, popular offline media shop)
http://www.bulkmedia.co.kr (small, but popular media shop)
There is no good English site about South Korean computer markets as far as I know and the above ones are all in Korean Hangul (not Chinese.)
PC Bang's in Seoul are usually cheap, mostly under US$1 per hour (though much more expensive than in China), but better choose a good one to avoid smokers and noisy children. There are many places that have wireless computing, especially at the places in Seoul where people move a lot like around universities and subway stations but I've never experimented myself.