Not many thoughts on the design itself, seems okay.
But the site, When you add your social networks, in the dropdown list you should have it removing the ones you've added as you go along. Or, remove the dropdown alltogether and have a list with text boxes, and either "update all" (For the ones you've entered) and update per each social network. Perhaps with the ones like Twitter, that have API's, perhaps code some pages to class as apps to post status' etc to these websites all in one place. Just like you have the option to receieve them.
Also have on the "My page" display the email in an image, like Facebook does to prevent spam bots. Simple thing too, make the links on the my page as _blank targets.
I like the idea though. I was thinking of something myself, just never got around to it.