I've actually taught online before, in Thailand.
I was working with Berlitz and their BVC, living in Thailand but teaching students in Japan. It was A LOT of fun! They had created a whole online program, it wasn't just though Skype, though that is a good way to do it.
Online programs are starting to spring up all over the place and many of the big companies are jumping on the trend. I know that both Berlitz and Wall Street Institute are doing them.
There was a company in Japan call The Nova Group that was doing 24/7 online classes but they... well... TheStar.com | News | ESL teachers left in limbo in Japan
It's a GREAT idea though! I wish you the best of luck with it!