I have a small project for you to develop in your free time a Magento Extension for single sign on using k networks, below i have given details of each of the social networks with a link
SNS Single Sign-on
1) Daum
[login to view URL]
2) Kakao
[login to view URL]시작하기-3_-앱을-실행합니다_
3) Naver
[login to view URL]
The above are all in Korea, but you should not have to much trouble as there are code examples and using google translate should be ok, let me know if you need any help.
I would like it to work just like this > [login to view URL] - if you wanted you could look at extending this plugin to include the above Korean social networks, then we could release our version to the Korean Market,
or you might want to build a version from scratch I will leave this up to you.
so to have facebook twitter and google+ would be good too..