I want my web application, which is built with Ruby on Rails, to communicate with the Facebook Social Graph API, but I am aware of that I need some kind of authorization to achieve that.
So, do I need to build OAuth authentication for my application to make use of auto-publishing messages on the user's Facebook wall? If not, how could I integrate the social features into my web application?
The web application already has an existing user base; could I also allow my application to get Facebook access? If yes, how?
I would appreciate examples of sites who do this kind of integration really well, also with other services like Twitter, LinkedIn, etc..