Well, if having your internet at home and work is NOT enough, you may want to work hard at getting to an English speaking agent at KT or otherwise (I think SK has a version of it too) to get it. WiBro is a mobile & wireless version of an ISP available in Korea (at least). More details are here: http://en.wikipedia.org/wiki/WiBro
Basically, from what I hear, you can get Internet access on transport like on the high speed KTX train up and down the peninsula, your bus rides, etc. You have to buy the modem though, from what I heard. A guy I know who runs TechnoKimchi.com has gotten it a while back. He may have more stories to say about his service.
I called up the number on the KT website (080.000.1472) and was transferred twice when I said “Young-uh Hahr-soo-ee-so-yo?” It means, can you “do English” literally. When I finally got the agent who sounded a bit worse than my EC2 students (2nd lowest level at CDI), I was able to get out of her that it is available. I asked when the service was available throughout the country and she said “a few months ago.” Well, a few months ago, I asked the KT Plaza I signed up for my Nespot service I have right now (which I’ve barely used, but fortunately only costs 15,000 won a month) and they said they didn’t have it at the time. I think it was just in the past couple of months it became available. She quoted 2 service plans at like 16,000 won and 28,000 won or so, just as a heads up.