[redcopper]

Hi livinginkorea,
I'm thinking of doing the same and have been able to chat with some korean and chinese friends over the web through MS Messenger (video/audio) so that part's easy enough. That's the good thing about living in a country with almost universal broadband.
I've also seen a course book from a Korean language institute which does a 10 minute a day phone-in English lesson but using cassette tapes and not human teaching.That gave me some ideas, particularly for phone-in English where 10 minutes one-one is a lot of time.
The main problem as I see it is advertising. To advertise in the Korean Herald is about 300,000 for a week and all the other outlets I've seen are similar so unless you have a good supply of contacts to work from....
For me living in the far south and in the countryside I have basically only that way, as word of mouth advertising is possible but not particularly effective. I am however exploring other means but will need to vastly improve my Korean if I am to succeed.
Not much in the way of actual experience but thought you might like to know you are not the only one thinking along these lines.